diff --git a/src/addons/blog/pages/edit-entry/edit-entry.ts b/src/addons/blog/pages/edit-entry/edit-entry.ts
index 3858ebdbe..5f732f19c 100644
--- a/src/addons/blog/pages/edit-entry/edit-entry.ts
+++ b/src/addons/blog/pages/edit-entry/edit-entry.ts
@@ -41,7 +41,7 @@ import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreSync } from '@services/sync';
 import { CoreDomUtils } from '@services/utils/dom';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { CoreForms } from '@singletons/form';
@@ -258,7 +258,7 @@ export default class AddonBlogEditEntryPage implements CanLeave, OnInit, OnDestr
 
             return selectedEntry;
         } catch (error) {
-            if (!params.filters || CoreUtils.isWebServiceError(error)) {
+            if (!params.filters || CoreWSError.isWebServiceError(error)) {
                 // Cannot get the entry, reject.
                 throw error;
             }
@@ -336,7 +336,7 @@ export default class AddonBlogEditEntryPage implements CanLeave, OnInit, OnDestr
 
                 return await this.saveEntry({ attachmentsId: attachmentsid });
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // It's a WebService error, the user cannot send the message so don't store it.
                     CoreDomUtils.showErrorModalDefault(error, 'Error updating entry.');
 
@@ -361,7 +361,7 @@ export default class AddonBlogEditEntryPage implements CanLeave, OnInit, OnDestr
             const attachmentsId = await this.uploadOrStoreFiles({ created });
             await this.saveEntry({ created, attachmentsId });
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 CoreDomUtils.showErrorModalDefault(error, 'Error creating entry.');
 
diff --git a/src/addons/blog/services/blog-sync.ts b/src/addons/blog/services/blog-sync.ts
index 953ab5564..e34a43b18 100644
--- a/src/addons/blog/services/blog-sync.ts
+++ b/src/addons/blog/services/blog-sync.ts
@@ -17,7 +17,7 @@ import { CoreSyncBaseProvider, CoreSyncBlockedError } from '@classes/base-sync';
 import { CoreFileUploader } from '@features/fileuploader/services/fileuploader';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { ADDON_BLOG_AUTO_SYNCED, ADDON_BLOG_SYNC_ID } from '../constants';
@@ -129,7 +129,7 @@ import { AddonBlogOfflineEntryDBRecord } from './database/blog';
                 await AddonBlogOffline.deleteOfflineEntryRecord({ created: entry.created }, siteId);
                 result.updated = true;
             } catch (error) {
-                if (!error || !CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
@@ -223,7 +223,7 @@ import { AddonBlogOfflineEntryDBRecord } from './database/blog';
                     entriesToSync = entriesPendingToSync;
                 }
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
diff --git a/src/addons/blog/services/blog.ts b/src/addons/blog/services/blog.ts
index 61e9db79c..45b5bb0b7 100644
--- a/src/addons/blog/services/blog.ts
+++ b/src/addons/blog/services/blog.ts
@@ -27,6 +27,7 @@ import { CoreStatusWithWarningsWSResponse, CoreWSExternalFile, CoreWSExternalWar
 import { makeSingleton } from '@singletons';
 import { AddonBlogOffline, AddonBlogOfflineEntry } from './blog-offline';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 const ROOT_CACHE_KEY = 'addonBlog:';
 
@@ -121,7 +122,7 @@ export class AddonBlogProvider {
         try {
             await this.addEntryOnline(params, siteId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return await storeOffline();
             }
@@ -177,7 +178,7 @@ export class AddonBlogProvider {
         try {
             await this.updateEntryOnline(params, siteId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return await storeOffline();
             }
@@ -232,7 +233,7 @@ export class AddonBlogProvider {
             await this.deleteEntryOnline(params, siteId);
             await CorePromiseUtils.ignoreErrors(AddonBlogOffline.unmarkEntryAsRemoved(params.entryid));
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return await AddonBlogOffline.markEntryAsRemoved({ id: params.entryid, subject }, siteId);
             }
diff --git a/src/addons/calendar/services/calendar-sync.ts b/src/addons/calendar/services/calendar-sync.ts
index e29ac63ce..d82383b8e 100644
--- a/src/addons/calendar/services/calendar-sync.ts
+++ b/src/addons/calendar/services/calendar-sync.ts
@@ -36,6 +36,7 @@ import {
     ADDON_CALENDAR_SYNC_ID,
 } from '../constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service to sync calendar.
@@ -219,7 +220,7 @@ export class AddonCalendarSyncProvider extends CoreSyncBaseProvider<AddonCalenda
                 await Promise.all(promises);
             } catch (error) {
 
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Local error, reject.
                     throw error;
                 }
@@ -284,7 +285,7 @@ export class AddonCalendarSyncProvider extends CoreSyncBaseProvider<AddonCalenda
             return AddonCalendarOffline.deleteEvent(event.id, siteId);
 
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Local error, reject.
                 throw error;
             }
diff --git a/src/addons/calendar/services/calendar.ts b/src/addons/calendar/services/calendar.ts
index 77f7156e4..00e9d623e 100644
--- a/src/addons/calendar/services/calendar.ts
+++ b/src/addons/calendar/services/calendar.ts
@@ -186,7 +186,7 @@ export class AddonCalendarProvider {
 
             return true;
         } catch (error) {
-            if (error && !CoreUtils.isWebServiceError(error)) {
+            if (error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
@@ -1540,7 +1540,7 @@ export class AddonCalendarProvider {
 
             return ({ sent: true, event });
         } catch (error) {
-            if (error && !CoreUtils.isWebServiceError(error)) {
+            if (error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
diff --git a/src/addons/coursecompletion/services/coursecompletion.ts b/src/addons/coursecompletion/services/coursecompletion.ts
index ceddb0d5b..2c3094379 100644
--- a/src/addons/coursecompletion/services/coursecompletion.ts
+++ b/src/addons/coursecompletion/services/coursecompletion.ts
@@ -15,7 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreLogger } from '@singletons/logger';
 import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreCourseAnyCourseData, CoreCourses } from '@features/courses/services/courses';
 import { CoreSite  } from '@classes/sites/site';
 import { CoreStatusWithWarningsWSResponse, CoreWSExternalWarning } from '@services/ws';
@@ -284,7 +284,7 @@ export class AddonCourseCompletionProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WS returned an error, plugin is not enabled.
                 return false;
             }
diff --git a/src/addons/messages/services/messages-sync.ts b/src/addons/messages/services/messages-sync.ts
index 765d52a96..dd0c0991a 100644
--- a/src/addons/messages/services/messages-sync.ts
+++ b/src/addons/messages/services/messages-sync.ts
@@ -22,7 +22,7 @@ import {
     AddonMessagesGetMessagesWSParams,
 } from './messages';
 import { CoreEvents } from '@singletons/events';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreSites } from '@services/sites';
 import { CoreNetwork } from '@services/network';
@@ -238,7 +238,7 @@ export class AddonMessagesSyncProvider extends CoreSyncBaseProvider<AddonMessage
                     await AddonMessages.sendMessageOnline(userId, text, siteId);
                 }
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Error sending, stop execution.
                     if (CoreNetwork.isOnline()) {
                         // App is online, unmark deviceoffline if marked.
diff --git a/src/addons/messages/services/messages.ts b/src/addons/messages/services/messages.ts
index 680a49ed8..bce46a176 100644
--- a/src/addons/messages/services/messages.ts
+++ b/src/addons/messages/services/messages.ts
@@ -23,7 +23,6 @@ import {
     AddonMessagesOfflineConversationMessagesDBRecordFormatted,
     AddonMessagesOfflineMessagesDBRecordFormatted,
 } from './messages-offline';
-import { CoreUtils } from '@services/utils/utils';
 import { CoreTimeUtils } from '@services/utils/time';
 import { CoreEvents } from '@singletons/events';
 import { CoreSite } from '@classes/sites/site';
@@ -2531,7 +2530,7 @@ export class AddonMessagesProvider {
                 message: result,
             };
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 throw error;
             }
@@ -2662,7 +2661,7 @@ export class AddonMessagesProvider {
                 message: result,
             };
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 throw error;
             }
diff --git a/src/addons/mod/assign/pages/edit/edit.ts b/src/addons/mod/assign/pages/edit/edit.ts
index 14526008a..811a677d8 100644
--- a/src/addons/mod/assign/pages/edit/edit.ts
+++ b/src/addons/mod/assign/pages/edit/edit.ts
@@ -36,7 +36,7 @@ import {
 import { AddonModAssignHelper } from '../../services/assign-helper';
 import { AddonModAssignOffline } from '../../services/assign-offline';
 import { AddonModAssignSync } from '../../services/assign-sync';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreWSExternalFile } from '@services/ws';
 import { CoreAnalytics, CoreAnalyticsEventType } from '@services/analytics';
 import {
@@ -344,7 +344,7 @@ export class AddonModAssignEditPage implements OnInit, OnDestroy, CanLeave {
                 this.hasOffline,
             );
         } catch (error) {
-            if (this.allowOffline && !this.saveOffline && !CoreUtils.isWebServiceError(error)) {
+            if (this.allowOffline && !this.saveOffline && !CoreWSError.isWebServiceError(error)) {
                 // Cannot submit in online, prepare for offline usage.
                 this.saveOffline = true;
 
diff --git a/src/addons/mod/assign/services/assign-sync.ts b/src/addons/mod/assign/services/assign-sync.ts
index 602d673f9..43923bd82 100644
--- a/src/addons/mod/assign/services/assign-sync.ts
+++ b/src/addons/mod/assign/services/assign-sync.ts
@@ -33,7 +33,7 @@ import {
 } from './assign-offline';
 import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreNetwork } from '@services/network';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreGradesFormattedItem, CoreGradesHelper } from '@features/grades/services/grades-helper';
@@ -360,7 +360,7 @@ export class AddonModAssignSyncProvider extends CoreCourseActivitySyncBaseProvid
             // Submission data sent, update cached data. No need to block the user for this.
             AddonModAssign.getSubmissionStatus(assign.id, options);
         } catch (error) {
-            if (!error || !CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Local error, reject.
                 throw error;
             }
@@ -511,7 +511,7 @@ export class AddonModAssignSyncProvider extends CoreCourseActivitySyncBaseProvid
 
             await CorePromiseUtils.allPromises(promises);
         } catch (error) {
-            if (!error || !CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Local error, reject.
                 throw error;
             }
diff --git a/src/addons/mod/assign/services/assign.ts b/src/addons/mod/assign/services/assign.ts
index a5a4caf68..488b67587 100644
--- a/src/addons/mod/assign/services/assign.ts
+++ b/src/addons/mod/assign/services/assign.ts
@@ -24,7 +24,6 @@ import { CoreTimeUtils } from '@services/utils/time';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreError } from '@classes/errors/error';
 import { CoreNetwork } from '@services/network';
-import { CoreUtils } from '@services/utils/utils';
 import { AddonModAssignOffline } from './assign-offline';
 import { AddonModAssignSubmissionDelegate } from './submission-delegate';
 import { CoreComments } from '@features/comments/services/comments';
@@ -1020,7 +1019,7 @@ export class AddonModAssignProvider {
 
             return true;
         } catch (error) {
-            if (allowOffline && error && !CoreUtils.isWebServiceError(error)) {
+            if (allowOffline && error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
@@ -1130,7 +1129,7 @@ export class AddonModAssignProvider {
 
             return true;
         } catch (error) {
-            if (error && !CoreUtils.isWebServiceError(error)) {
+            if (error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
@@ -1238,7 +1237,7 @@ export class AddonModAssignProvider {
 
             return true;
         } catch (error) {
-            if (error && !CoreUtils.isWebServiceError(error)) {
+            if (error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
@@ -1379,7 +1378,7 @@ export class AddonModAssignProvider {
 
             return true;
         } catch (error) {
-            if (error && !CoreUtils.isWebServiceError(error)) {
+            if (error && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
diff --git a/src/addons/mod/choice/services/choice-sync.ts b/src/addons/mod/choice/services/choice-sync.ts
index 94e5ab90e..8c938276a 100644
--- a/src/addons/mod/choice/services/choice-sync.ts
+++ b/src/addons/mod/choice/services/choice-sync.ts
@@ -20,7 +20,7 @@ import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModChoice } from './choice';
@@ -195,7 +195,7 @@ export class AddonModChoiceSyncProvider extends CoreCourseActivitySyncBaseProvid
 
             await AddonModChoiceOffline.deleteResponse(choiceId, siteId, userId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, reject.
                 throw error;
             }
diff --git a/src/addons/mod/choice/services/choice.ts b/src/addons/mod/choice/services/choice.ts
index 3c31c625a..460a3bfea 100644
--- a/src/addons/mod/choice/services/choice.ts
+++ b/src/addons/mod/choice/services/choice.ts
@@ -20,7 +20,6 @@ import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreFilepool } from '@services/filepool';
 import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
 import { CoreStatusWithWarningsWSResponse, CoreWSExternalFile, CoreWSExternalWarning } from '@services/ws';
 import { makeSingleton, Translate } from '@singletons';
 import { AddonModChoiceOffline } from './choice-offline';
@@ -121,7 +120,7 @@ export class AddonModChoiceProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
@@ -434,7 +433,7 @@ export class AddonModChoiceProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
diff --git a/src/addons/mod/data/pages/edit/edit.ts b/src/addons/mod/data/pages/edit/edit.ts
index 610ad8eef..3394b93fb 100644
--- a/src/addons/mod/data/pages/edit/edit.ts
+++ b/src/addons/mod/data/pages/edit/edit.ts
@@ -45,6 +45,7 @@ import { CoreTime } from '@singletons/time';
 import { CoreAnalytics, CoreAnalyticsEventType } from '@services/analytics';
 import { ADDON_MOD_DATA_COMPONENT, ADDON_MOD_DATA_ENTRY_CHANGED, AddonModDataTemplateType } from '../../constants';
 import { CoreLoadings } from '@services/loadings';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Page that displays the view edit page.
@@ -303,7 +304,7 @@ export class AddonModDataEditPage implements OnInit {
                         this.offline,
                     );
                 } catch (error) {
-                    if (this.offline || CoreUtils.isWebServiceError(error)) {
+                    if (this.offline || CoreWSError.isWebServiceError(error)) {
                         throw error;
                     }
 
diff --git a/src/addons/mod/data/services/data-sync.ts b/src/addons/mod/data/services/data-sync.ts
index 224f8002d..7f7884cf2 100644
--- a/src/addons/mod/data/services/data-sync.ts
+++ b/src/addons/mod/data/services/data-sync.ts
@@ -35,6 +35,7 @@ import { AddonModDataOffline, AddonModDataOfflineAction } from './data-offline';
 import { ADDON_MOD_DATA_AUTO_SYNCED, ADDON_MOD_DATA_COMPONENT, AddonModDataAction } from '../constants';
 import { CoreText } from '@singletons/text';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service to sync databases.
@@ -294,7 +295,7 @@ export class AddonModDataSyncProvider extends CoreCourseActivitySyncBaseProvider
 
                 timemodified = entry.entry.timemodified;
             } catch (error) {
-                if (error && CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means the entry has been deleted.
                     timemodified = -1;
                 } else {
@@ -326,7 +327,7 @@ export class AddonModDataSyncProvider extends CoreCourseActivitySyncBaseProvider
                 await AddonModData.deleteEntryOnline(entryId, siteId);
                 entryResult.deleted = true;
             } catch (error) {
-                if (error && CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means it cannot be performed. Discard.
                     entryResult.discardError = CoreErrorHelper.getErrorMessageFromError(error);
                 } else {
@@ -384,7 +385,7 @@ export class AddonModDataSyncProvider extends CoreCourseActivitySyncBaseProvider
                     await AddonModData.editEntryOnline(entryId, editAction.fields, siteId);
                 }
             } catch (error) {
-                if (error && CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means it cannot be performed. Discard.
                     entryResult.discardError = CoreErrorHelper.getErrorMessageFromError(error);
                 } else {
@@ -402,7 +403,7 @@ export class AddonModDataSyncProvider extends CoreCourseActivitySyncBaseProvider
             try {
                 await AddonModData.approveEntryOnline(entryId, approveAction.action == AddonModDataAction.APPROVE, siteId);
             } catch (error) {
-                if (error && CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means it cannot be performed. Discard.
                     entryResult.discardError = CoreErrorHelper.getErrorMessageFromError(error);
                 } else {
diff --git a/src/addons/mod/data/services/data.ts b/src/addons/mod/data/services/data.ts
index 89292ac97..1ba6d875d 100644
--- a/src/addons/mod/data/services/data.ts
+++ b/src/addons/mod/data/services/data.ts
@@ -36,6 +36,7 @@ import {
 } from '../constants';
 import { CoreCacheUpdateFrequency } from '@/core/constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 declare module '@singletons/events' {
 
@@ -124,7 +125,7 @@ export class AddonModDataProvider {
 
             return result;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
@@ -213,7 +214,7 @@ export class AddonModDataProvider {
                 sent: true,
             };
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
@@ -308,7 +309,7 @@ export class AddonModDataProvider {
         try {
             await this.deleteEntryOnline(entryId, siteId);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
@@ -424,7 +425,7 @@ export class AddonModDataProvider {
 
             return result;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
diff --git a/src/addons/mod/feedback/pages/form/form.ts b/src/addons/mod/feedback/pages/form/form.ts
index 388f7d37c..16b54cac0 100644
--- a/src/addons/mod/feedback/pages/form/form.ts
+++ b/src/addons/mod/feedback/pages/form/form.ts
@@ -45,6 +45,7 @@ import {
 import { CoreLoadings } from '@services/loadings';
 import { CoreError } from '@classes/errors/error';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Page that displays feedback form.
@@ -219,7 +220,7 @@ export class AddonModFeedbackFormPage implements OnInit, OnDestroy, CanLeave {
         try {
             this.access = await AddonModFeedback.getFeedbackAccessInformation(this.feedback.id, options);
         } catch (error) {
-            if (this.offline || CoreUtils.isWebServiceError(error)) {
+            if (this.offline || CoreWSError.isWebServiceError(error)) {
                 // Already offline or shouldn't go offline, fail.
                 throw error;
             }
@@ -246,7 +247,7 @@ export class AddonModFeedbackFormPage implements OnInit, OnDestroy, CanLeave {
         try {
             return await AddonModFeedback.getResumePage(this.feedback.id, options);
         } catch (error) {
-            if (this.offline || CoreUtils.isWebServiceError(error)) {
+            if (this.offline || CoreWSError.isWebServiceError(error)) {
                 // Already offline or shouldn't go offline, fail.
                 throw error;
             }
@@ -314,7 +315,7 @@ export class AddonModFeedbackFormPage implements OnInit, OnDestroy, CanLeave {
         try {
             response = await AddonModFeedback.getPageItemsWithValues(this.feedback.id, page, options);
         } catch (error) {
-            if (this.offline || CoreUtils.isWebServiceError(error)) {
+            if (this.offline || CoreWSError.isWebServiceError(error)) {
                 // Already offline or shouldn't go offline, fail.
                 throw error;
             }
diff --git a/src/addons/mod/feedback/services/feedback-sync.ts b/src/addons/mod/feedback/services/feedback-sync.ts
index 9dc1c555f..bb7e2ce28 100644
--- a/src/addons/mod/feedback/services/feedback-sync.ts
+++ b/src/addons/mod/feedback/services/feedback-sync.ts
@@ -21,7 +21,7 @@ import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModFeedback, AddonModFeedbackWSFeedback } from './feedback';
@@ -266,7 +266,7 @@ export class AddonModFeedbackSyncProvider extends CoreCourseActivitySyncBaseProv
 
             await AddonModFeedbackOffline.deleteFeedbackPageResponses(feedback.id, data.page, siteId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, reject.
                 throw error;
             }
diff --git a/src/addons/mod/feedback/services/feedback.ts b/src/addons/mod/feedback/services/feedback.ts
index 6d781f54d..a01b4e90e 100644
--- a/src/addons/mod/feedback/services/feedback.ts
+++ b/src/addons/mod/feedback/services/feedback.ts
@@ -36,6 +36,7 @@ import {
 } from '../constants';
 import { CoreCacheUpdateFrequency } from '@/core/constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service that provides some features for feedbacks.
@@ -1195,7 +1196,7 @@ export class AddonModFeedbackProvider {
         try {
             return await this.processPageOnline(feedbackId, page, responses, !!options.goPrevious, options.siteId);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
diff --git a/src/addons/mod/forum/classes/forum-discussions-source.ts b/src/addons/mod/forum/classes/forum-discussions-source.ts
index fe881492e..079cd4be1 100644
--- a/src/addons/mod/forum/classes/forum-discussions-source.ts
+++ b/src/addons/mod/forum/classes/forum-discussions-source.ts
@@ -16,7 +16,7 @@ import { Params } from '@angular/router';
 import { CoreRoutedItemsManagerSource } from '@classes/items-management/routed-items-manager-source';
 import { CoreUser } from '@features/user/services/user';
 import { CoreGroupInfo, CoreGroups } from '@services/groups';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import {
     AddonModForum,
     AddonModForumCanAddDiscussion,
@@ -246,7 +246,7 @@ export class AddonModForumDiscussionsSource extends CoreRoutedItemsManagerSource
             canLoadMore = response.canLoadMore;
             this.errorLoadingDiscussions = false;
         } catch (error) {
-            if (page > 0 || CoreUtils.isWebServiceError(error)) {
+            if (page > 0 || CoreWSError.isWebServiceError(error)) {
                 throw error;
             }
 
diff --git a/src/addons/mod/forum/components/post/post.ts b/src/addons/mod/forum/components/post/post.ts
index da0d15195..d2d54aac7 100644
--- a/src/addons/mod/forum/components/post/post.ts
+++ b/src/addons/mod/forum/components/post/post.ts
@@ -59,6 +59,7 @@ import { CorePopovers } from '@services/popovers';
 import { CoreLoadings } from '@services/loadings';
 import { CoreWSFile } from '@services/ws';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Components that shows a discussion post, its attachments and the action buttons allowed (reply, etc.).
@@ -554,7 +555,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
             return { attachments, saveOffline: false };
         } catch (error) {
             // Cannot upload them in online, save them in offline.
-            if (!this.forum.id || CoreUtils.isWebServiceError(error)) {
+            if (!this.forum.id || CoreWSError.isWebServiceError(error)) {
                 // Cannot store them in offline. Reject.
                 throw error;
             }
diff --git a/src/addons/mod/forum/services/forum-helper.ts b/src/addons/mod/forum/services/forum-helper.ts
index 734c589be..c796d23f3 100644
--- a/src/addons/mod/forum/services/forum-helper.ts
+++ b/src/addons/mod/forum/services/forum-helper.ts
@@ -33,6 +33,7 @@ import { AddonModForumDiscussionOptions, AddonModForumOffline, AddonModForumOffl
 import { CoreFileEntry } from '@services/file-helper';
 import { ADDON_MOD_FORUM_ALL_GROUPS, ADDON_MOD_FORUM_COMPONENT } from '../constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service that provides some features for forums.
@@ -107,7 +108,7 @@ export class AddonModForumHelperProvider {
             try {
                 await Promise.all(promises);
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
@@ -161,7 +162,7 @@ export class AddonModForumHelperProvider {
         if (errors.length == groupIds.length) {
             // All requests have failed.
             for (let i = 0; i < errors.length; i++) {
-                if (CoreUtils.isWebServiceError(errors[i]) || (attachments && attachments.length > 0)) {
+                if (CoreWSError.isWebServiceError(errors[i]) || (attachments && attachments.length > 0)) {
                     // The WebService has thrown an error or offline not supported, reject.
                     throw errors[i];
                 }
diff --git a/src/addons/mod/forum/services/forum-sync.ts b/src/addons/mod/forum/services/forum-sync.ts
index 261b07ec3..bcc5f1134 100644
--- a/src/addons/mod/forum/services/forum-sync.ts
+++ b/src/addons/mod/forum/services/forum-sync.ts
@@ -39,6 +39,7 @@ import {
     ADDON_MOD_FORUM_MANUAL_SYNCED,
 } from '../constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 declare module '@singletons/events' {
 
@@ -273,7 +274,7 @@ export class AddonModForumSyncProvider extends CoreCourseActivitySyncBaseProvide
                 if (errors.length === groupIds.length) {
                     // All requests have failed, reject if errors were not returned by WS.
                     for (const error of errors) {
-                        if (!CoreUtils.isWebServiceError(error)) {
+                        if (!CoreWSError.isWebServiceError(error)) {
                             throw error;
                         }
                     }
@@ -490,7 +491,7 @@ export class AddonModForumSyncProvider extends CoreCourseActivitySyncBaseProvide
 
                     await this.deleteReply(forumId, reply.postid, siteId, userId);
                 } catch (error) {
-                    if (!CoreUtils.isWebServiceError(error)) {
+                    if (!CoreWSError.isWebServiceError(error)) {
                         throw error;
                     }
 
diff --git a/src/addons/mod/forum/services/forum.ts b/src/addons/mod/forum/services/forum.ts
index 8ffbc4a9b..e933b4eee 100644
--- a/src/addons/mod/forum/services/forum.ts
+++ b/src/addons/mod/forum/services/forum.ts
@@ -51,6 +51,7 @@ import {
 } from '../constants';
 import { CoreCacheUpdateFrequency } from '@/core/constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 declare module '@singletons/events' {
 
@@ -1113,7 +1114,7 @@ export class AddonModForumProvider {
 
             return true;
         } catch (error) {
-            if (allowOffline && !CoreUtils.isWebServiceError(error)) {
+            if (allowOffline && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             } else {
diff --git a/src/addons/mod/glossary/pages/edit/edit.ts b/src/addons/mod/glossary/pages/edit/edit.ts
index 4c2aa09fe..59b62abbc 100644
--- a/src/addons/mod/glossary/pages/edit/edit.ts
+++ b/src/addons/mod/glossary/pages/edit/edit.ts
@@ -25,7 +25,7 @@ import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreText } from '@singletons/text';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { Translate } from '@singletons';
 import { CoreEventObserver, CoreEvents } from '@singletons/events';
 import { CoreForms } from '@singletons/form';
@@ -522,7 +522,7 @@ class AddonModGlossaryNewFormHandler extends AddonModGlossaryFormHandler {
             try {
                 onlineAttachments = await this.uploadAttachments(glossary);
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
diff --git a/src/addons/mod/glossary/services/glossary-sync.ts b/src/addons/mod/glossary/services/glossary-sync.ts
index ab33c570f..faadf0159 100644
--- a/src/addons/mod/glossary/services/glossary-sync.ts
+++ b/src/addons/mod/glossary/services/glossary-sync.ts
@@ -22,7 +22,7 @@ import { CoreRatingSync } from '@features/rating/services/rating-sync';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModGlossary } from './glossary';
@@ -207,7 +207,7 @@ export class AddonModGlossarySyncProvider extends CoreCourseActivitySyncBaseProv
 
                 await this.deleteAddEntry(glossaryId, data.concept, data.timecreated, siteId);
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Couldn't connect to server, reject.
                     throw error;
                 }
diff --git a/src/addons/mod/glossary/services/glossary.ts b/src/addons/mod/glossary/services/glossary.ts
index d7e3777e2..8e04dfc6c 100644
--- a/src/addons/mod/glossary/services/glossary.ts
+++ b/src/addons/mod/glossary/services/glossary.ts
@@ -39,6 +39,7 @@ import {
 } from '../constants';
 import { CoreCacheUpdateFrequency } from '@/core/constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service that provides some features for glossaries.
@@ -874,7 +875,7 @@ export class AddonModGlossaryProvider {
 
             return entryId;
         } catch (error) {
-            if (otherOptions.allowOffline && !CoreUtils.isWebServiceError(error)) {
+            if (otherOptions.allowOffline && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
diff --git a/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts b/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
index 93bb9c0c8..90f43d75b 100644
--- a/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
+++ b/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
@@ -22,7 +22,6 @@ import { CoreXAPIOffline } from '@features/xapi/services/offline';
 import { CoreXAPI, XAPI_STATE_DELETED } from '@features/xapi/services/xapi';
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import {
@@ -196,7 +195,7 @@ export class AddonModH5PActivitySyncProvider extends CoreCourseActivitySyncBaseP
             h5pActivity = await AddonModH5PActivity.getH5PActivityByContextId(courseId, contextId, { siteId });
         } catch (error) {
             if (
-                CoreUtils.isWebServiceError(error) ||
+                CoreWSError.isWebServiceError(error) ||
                 CoreErrorHelper.getErrorMessageFromError(error) === Translate.instant('core.course.modulenotfound')
             ) {
                 // Activity no longer accessible. Delete the data and finish the sync.
@@ -253,7 +252,7 @@ export class AddonModH5PActivitySyncProvider extends CoreCourseActivitySyncBaseP
 
                 await CoreXAPIOffline.deleteStatements(entry.id, siteId);
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
@@ -313,7 +312,7 @@ export class AddonModH5PActivitySyncProvider extends CoreCourseActivitySyncBaseP
         } catch (error) {
             // Error getting attempts. If the WS has thrown an exception it means the user cannot retrieve the attempts for
             // some reason (it shouldn't happen), continue synchronizing in that case.
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 throw error;
             }
         }
@@ -364,7 +363,7 @@ export class AddonModH5PActivitySyncProvider extends CoreCourseActivitySyncBaseP
                     siteId,
                 });
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
diff --git a/src/addons/mod/h5pactivity/services/h5pactivity.ts b/src/addons/mod/h5pactivity/services/h5pactivity.ts
index 68ebb7ab3..7065efe8e 100644
--- a/src/addons/mod/h5pactivity/services/h5pactivity.ts
+++ b/src/addons/mod/h5pactivity/services/h5pactivity.ts
@@ -16,7 +16,6 @@ import { Injectable } from '@angular/core';
 
 import { CoreSites, CoreSitesCommonWSOptions, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreWSExternalWarning, CoreWSExternalFile, CoreWSFile } from '@services/ws';
-import { CoreUtils } from '@services/utils/utils';
 import { CoreSite } from '@classes/sites/site';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreH5P } from '@features/h5p/services/h5p';
@@ -380,7 +379,7 @@ export class AddonModH5PActivityProvider {
 
             return this.formatAttemptResults(response.attempts[0]);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 throw error;
             }
 
@@ -634,7 +633,7 @@ export class AddonModH5PActivityProvider {
 
             return this.formatUserAttempts(response.usersattempts[0]);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 throw error;
             }
 
diff --git a/src/addons/mod/lesson/pages/player/player.ts b/src/addons/mod/lesson/pages/player/player.ts
index fd5b2be34..328921c0d 100644
--- a/src/addons/mod/lesson/pages/player/player.ts
+++ b/src/addons/mod/lesson/pages/player/player.ts
@@ -56,6 +56,7 @@ import { CoreAnalytics, CoreAnalyticsEventType } from '@services/analytics';
 import { ADDON_MOD_LESSON_COMPONENT, AddonModLessonJumpTo } from '../../constants';
 import { CoreModals } from '@services/modals';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Page that allows attempting and reviewing a lesson.
@@ -214,7 +215,7 @@ export class AddonModLessonPlayerPage implements OnInit, OnDestroy, CanLeave {
                 throw error;
             }
 
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // WebService returned an error, cannot perform the action.
                 throw error;
             }
@@ -356,7 +357,7 @@ export class AddonModLessonPlayerPage implements OnInit, OnDestroy, CanLeave {
             return true;
         } catch (error) {
 
-            if (this.review && this.retakeToReview && CoreUtils.isWebServiceError(error)) {
+            if (this.review && this.retakeToReview && CoreWSError.isWebServiceError(error)) {
                 // The user cannot review the retake. Unmark the retake as being finished in sync.
                 await AddonModLessonSync.deleteRetakeFinishedInSync(this.lesson!.id);
             }
diff --git a/src/addons/mod/lesson/pages/user-retake/user-retake.ts b/src/addons/mod/lesson/pages/user-retake/user-retake.ts
index a76fdd9a1..8a7510062 100644
--- a/src/addons/mod/lesson/pages/user-retake/user-retake.ts
+++ b/src/addons/mod/lesson/pages/user-retake/user-retake.ts
@@ -20,7 +20,7 @@ import { CoreNavigator } from '@services/navigator';
 import { CoreSites } from '@services/sites';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreText } from '@singletons/text';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreErrorHelper } from '@services/error-helper';
 import { Translate } from '@singletons';
 import {
     AddonModLesson,
@@ -103,7 +103,7 @@ export class AddonModLessonUserRetakePage implements OnInit {
             this.performLogView();
         } catch (error) {
             this.selectedRetake = this.previousSelectedRetake ?? this.selectedRetake;
-            CoreDomUtils.showErrorModal(CoreUtils.addDataNotDownloadedError(error, 'Error getting attempt.'));
+            CoreDomUtils.showErrorModal(CoreErrorHelper.addDataNotDownloadedError(error, 'Error getting attempt.'));
         } finally {
             this.loaded = true;
         }
diff --git a/src/addons/mod/lesson/services/lesson-sync.ts b/src/addons/mod/lesson/services/lesson-sync.ts
index 303f8df81..bdcfaf2d2 100644
--- a/src/addons/mod/lesson/services/lesson-sync.ts
+++ b/src/addons/mod/lesson/services/lesson-sync.ts
@@ -24,7 +24,7 @@ import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreTimeUtils } from '@services/utils/time';
 import { CoreUrl } from '@singletons/url';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModLessonRetakeFinishedInSyncDBRecord, RETAKES_FINISHED_SYNC_TABLE_NAME } from './database/lesson';
@@ -375,7 +375,7 @@ export class AddonModLessonSyncProvider extends CoreCourseActivitySyncBaseProvid
 
             await AddonModLessonOffline.deleteAttempt(lesson.id, retake, pageId, timemodified, siteId);
         } catch (error) {
-            if (!error || !CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server.
                 throw error;
             }
@@ -473,7 +473,7 @@ export class AddonModLessonSyncProvider extends CoreCourseActivitySyncBaseProvid
 
             await AddonModLessonOffline.deleteRetake(lessonId, siteId);
         } catch (error) {
-            if (!error || !CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server.
                 throw error;
             }
diff --git a/src/addons/mod/quiz/services/quiz-helper.ts b/src/addons/mod/quiz/services/quiz-helper.ts
index 8e9ae6d2c..db7699497 100644
--- a/src/addons/mod/quiz/services/quiz-helper.ts
+++ b/src/addons/mod/quiz/services/quiz-helper.ts
@@ -20,7 +20,7 @@ import { CoreCourse } from '@features/course/services/course';
 import { CoreNavigator } from '@services/navigator';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
 import { CoreDomUtils } from '@services/utils/dom';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { AddonModQuizAccessRuleDelegate } from './access-rules-delegate';
 import {
@@ -503,7 +503,7 @@ export class AddonModQuizHelperProvider {
 
             return attempt;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService returned an error, assume the preflight failed.
                 AddonModQuizAccessRuleDelegate.notifyPreflightCheckFailed(
                     rules,
diff --git a/src/addons/mod/survey/services/survey-sync.ts b/src/addons/mod/survey/services/survey-sync.ts
index e814a7427..d747a55aa 100644
--- a/src/addons/mod/survey/services/survey-sync.ts
+++ b/src/addons/mod/survey/services/survey-sync.ts
@@ -20,7 +20,7 @@ import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { getPrefetchHandlerInstance } from './handlers/prefetch';
@@ -185,7 +185,7 @@ export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvid
                 // Answers sent, delete them.
                 await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId, userId);
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Local error, reject.
                     throw error;
                 }
diff --git a/src/addons/mod/survey/services/survey.ts b/src/addons/mod/survey/services/survey.ts
index d781bdd4e..66e134471 100644
--- a/src/addons/mod/survey/services/survey.ts
+++ b/src/addons/mod/survey/services/survey.ts
@@ -19,7 +19,7 @@ import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreFilepool } from '@services/filepool';
 import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreStatusWithWarningsWSResponse, CoreWSExternalFile, CoreWSExternalWarning } from '@services/ws';
 import { makeSingleton, Translate } from '@singletons';
 import { AddonModSurveyOffline } from './survey-offline';
@@ -268,7 +268,7 @@ export class AddonModSurveyProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 throw error;
             }
diff --git a/src/addons/mod/wiki/services/wiki-sync.ts b/src/addons/mod/wiki/services/wiki-sync.ts
index 82ab78842..31b43cd2c 100644
--- a/src/addons/mod/wiki/services/wiki-sync.ts
+++ b/src/addons/mod/wiki/services/wiki-sync.ts
@@ -20,7 +20,7 @@ import { CoreNetwork } from '@services/network';
 import { CoreGroups } from '@services/groups';
 import { CoreSites } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModWikiPageDBRecord } from './database/wiki';
@@ -248,7 +248,7 @@ export class AddonModWikiSyncProvider extends CoreSyncBaseProvider<AddonModWikiS
                 // Delete the local page.
                 await AddonModWikiOffline.deleteNewPage(page.title, subwikiId, wikiId, userId, groupId, siteId);
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Couldn't connect to server, reject.
                     throw error;
                 }
diff --git a/src/addons/mod/wiki/services/wiki.ts b/src/addons/mod/wiki/services/wiki.ts
index f2b66ac16..85b76c7a4 100644
--- a/src/addons/mod/wiki/services/wiki.ts
+++ b/src/addons/mod/wiki/services/wiki.ts
@@ -20,7 +20,7 @@ import { CoreTagItem } from '@features/tag/services/tag';
 import { CoreNetwork } from '@services/network';
 import { CoreNavigator } from '@services/navigator';
 import { CoreSites, CoreSitesCommonWSOptions, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreWSExternalFile, CoreWSExternalWarning, CoreWSFile } from '@services/ws';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -719,7 +719,7 @@ export class AddonModWikiProvider {
             // Try to create it in online.
             return await this.newPageOnline(title, content, options);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that the page cannot be added.
                 throw error;
             }
diff --git a/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts b/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts
index cbb5f7696..982b56aab 100644
--- a/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts
+++ b/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts
@@ -44,6 +44,7 @@ import {
 import { toBoolean } from '@/core/transforms/boolean';
 import { CoreLoadings } from '@services/loadings';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Component that displays workshop assessment strategy form.
@@ -318,7 +319,7 @@ export class AddonModWorkshopAssessmentStrategyComponent implements OnInit, OnDe
                     saveOffline,
                 );
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
diff --git a/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts b/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts
index 8e884b84d..5908e9c2e 100644
--- a/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts
+++ b/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts
@@ -25,7 +25,7 @@ import { CoreSites } from '@services/sites';
 import { CoreSync } from '@services/sync';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreText } from '@singletons/text';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { CoreForms } from '@singletons/form';
@@ -376,7 +376,7 @@ export class AddonModWorkshopEditSubmissionPage implements OnInit, OnDestroy, Ca
                     false,
                 );
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     throw error;
                 }
 
diff --git a/src/addons/mod/workshop/services/workshop-sync.ts b/src/addons/mod/workshop/services/workshop-sync.ts
index c949cb5c1..ac6ddca21 100644
--- a/src/addons/mod/workshop/services/workshop-sync.ts
+++ b/src/addons/mod/workshop/services/workshop-sync.ts
@@ -22,7 +22,7 @@ import { CoreFileEntry } from '@services/file-helper';
 import { CoreSites } from '@services/sites';
 import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreErrorHelper } from '@services/error-helper';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { Translate, makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonModWorkshop,
@@ -372,7 +372,7 @@ export class AddonModWorkshopSyncProvider extends CoreSyncBaseProvider<AddonModW
                         await AddonModWorkshop.deleteSubmissionOnline(submissionId, siteId);
                 }
             } catch (error) {
-                if (error && CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means it cannot be performed. Discard.
                     discardError = CoreErrorHelper.getErrorMessageFromError(error);
                 }
@@ -471,7 +471,7 @@ export class AddonModWorkshopSyncProvider extends CoreSyncBaseProvider<AddonModW
 
             await AddonModWorkshop.updateAssessmentOnline(assessmentId, inputData, siteId);
         } catch (error) {
-            if (error && CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means it cannot be performed. Discard.
                 discardError = CoreErrorHelper.getErrorMessageFromError(error);
             } else {
@@ -544,7 +544,7 @@ export class AddonModWorkshopSyncProvider extends CoreSyncBaseProvider<AddonModW
                 siteId,
             );
         } catch (error) {
-            if (error && CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means it cannot be performed. Discard.
                 discardError = CoreErrorHelper.getErrorMessageFromError(error);
             } else {
@@ -612,7 +612,7 @@ export class AddonModWorkshopSyncProvider extends CoreSyncBaseProvider<AddonModW
                 siteId,
             );
         } catch (error) {
-            if (error && CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means it cannot be performed. Discard.
                 discardError = CoreErrorHelper.getErrorMessageFromError(error);
             } else {
diff --git a/src/addons/mod/workshop/services/workshop.ts b/src/addons/mod/workshop/services/workshop.ts
index da97e87e5..a6c7a4d3f 100644
--- a/src/addons/mod/workshop/services/workshop.ts
+++ b/src/addons/mod/workshop/services/workshop.ts
@@ -40,6 +40,7 @@ import {
 } from '@addons/mod/workshop/constants';
 import { CoreSiteWSPreSets } from '@classes/sites/authenticated-site';
 import { CoreCacheUpdateFrequency } from '@/core/constants';
+import { CoreWSError } from '@classes/errors/wserror';
 
 declare module '@singletons/events' {
 
@@ -708,7 +709,7 @@ export class AddonModWorkshopProvider {
         try {
             return await this.addSubmissionOnline(workshopId, title, content, attachmentsId as number, siteId);
         } catch (error) {
-            if (allowOffline && !CoreUtils.isWebServiceError(error)) {
+            if (allowOffline && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
@@ -808,7 +809,7 @@ export class AddonModWorkshopProvider {
         try {
             return await this.updateSubmissionOnline(submissionId, title, content, attachmentsId as number, siteId);
         } catch (error) {
-            if (allowOffline && !CoreUtils.isWebServiceError(error)) {
+            if (allowOffline && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
@@ -887,7 +888,7 @@ export class AddonModWorkshopProvider {
         try {
             return await this.deleteSubmissionOnline(submissionId, siteId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
@@ -1159,7 +1160,7 @@ export class AddonModWorkshopProvider {
 
             return true;
         } catch (error) {
-            if (allowOffline && !CoreUtils.isWebServiceError(error)) {
+            if (allowOffline && !CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
@@ -1236,7 +1237,7 @@ export class AddonModWorkshopProvider {
         try {
             return await this.evaluateSubmissionOnline(submissionId, feedbackText, published, gradeOver, siteId);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error or offline not supported, reject.
                 throw error;
             }
@@ -1326,7 +1327,7 @@ export class AddonModWorkshopProvider {
         try {
             return await this.evaluateAssessmentOnline(assessmentId, feedbackText, weight, gradingGradeOver, siteId);
         } catch (error) {
-            if (!CoreUtils.isWebServiceError(error)) {
+            if (!CoreWSError.isWebServiceError(error)) {
                 // Couldn't connect to server, store in offline.
                 return storeOffline();
             }
diff --git a/src/addons/notes/services/notes-sync.ts b/src/addons/notes/services/notes-sync.ts
index 1491360cc..c0e7e2547 100644
--- a/src/addons/notes/services/notes-sync.ts
+++ b/src/addons/notes/services/notes-sync.ts
@@ -18,7 +18,7 @@ import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCourses } from '@features/courses/services/courses';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { Translate, makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { AddonNotesDBRecord, AddonNotesDeletedDBRecord } from './database/notes';
@@ -179,7 +179,7 @@ export class AddonNotesSyncProvider extends CoreSyncBaseProvider<AddonNotesSyncR
 
             return;
         }).catch((error) => {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, this means the user cannot send notes.
                 errors.push(error);
 
@@ -203,7 +203,7 @@ export class AddonNotesSyncProvider extends CoreSyncBaseProvider<AddonNotesSyncR
 
         // Delete the notes.
         promises.push(AddonNotes.deleteNotesOnline(notesToDelete, courseId, siteId).catch((error) => {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, this means the user cannot send notes.
                 errors.push(error);
 
diff --git a/src/addons/notes/services/notes.ts b/src/addons/notes/services/notes.ts
index 89e935bad..802d4b9b1 100644
--- a/src/addons/notes/services/notes.ts
+++ b/src/addons/notes/services/notes.ts
@@ -17,7 +17,6 @@ import { CoreWSError } from '@classes/errors/wserror';
 import { CoreUser } from '@features/user/services/user';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
 import { CoreWSExternalWarning } from '@services/ws';
 import { makeSingleton, Translate } from '@singletons';
 import { AddonNotesOffline } from './notes-offline';
@@ -70,7 +69,7 @@ export class AddonNotesProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 throw error;
             }
@@ -173,7 +172,7 @@ export class AddonNotesProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the note so don't store it.
                 throw error;
             }
diff --git a/src/core/classes/element-controllers/MediaElementController.ts b/src/core/classes/element-controllers/MediaElementController.ts
index 3a67a6ceb..b4b6682ad 100644
--- a/src/core/classes/element-controllers/MediaElementController.ts
+++ b/src/core/classes/element-controllers/MediaElementController.ts
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import { CoreUtils } from '@services/utils/utils';
+import { CoreErrorHelper } from '@services/error-helper';
 import { ElementController } from './ElementController';
 import { CorePromisedValue } from '@classes/promised-value';
 import { CoreEventObserver, CoreEvents } from '@singletons/events';
@@ -70,7 +70,7 @@ export class MediaElementController extends ElementController {
 
             this.addPlaybackEventListeners(jsPlayer);
         } catch (error) {
-            CoreUtils.logUnhandledError('Error enabling media element', error);
+            CoreErrorHelper.logUnhandledError('Error enabling media element', error);
         }
     }
 
diff --git a/src/core/classes/errors/wserror.ts b/src/core/classes/errors/wserror.ts
index f34ac0587..c35d11b98 100644
--- a/src/core/classes/errors/wserror.ts
+++ b/src/core/classes/errors/wserror.ts
@@ -39,6 +39,39 @@ export class CoreWSError extends CoreError {
         this.backtrace = error.backtrace;
     }
 
+    /**
+     * Given an error returned by a WS call, check if the error is generated by the app or it has been returned by the WebService.
+     *
+     * @param error Error to check.
+     * @returns Whether the error was returned by the WebService.
+     */
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    static isWebServiceError(error: any): boolean {
+        return !!error && (
+            error.warningcode !== undefined ||
+            (
+                error.errorcode !== undefined && error.errorcode != 'userdeleted' && error.errorcode != 'upgraderunning' &&
+                error.errorcode != 'forcepasswordchangenotice' && error.errorcode != 'usernotfullysetup' &&
+                error.errorcode != 'sitepolicynotagreed' && error.errorcode != 'sitemaintenance' &&
+                error.errorcode != 'wsaccessusersuspended' && error.errorcode != 'wsaccessuserdeleted' &&
+                !this.isExpiredTokenError(error)
+            ) ||
+            !!error.status && error.status >= 400 // CoreHttpError, assume status 400 and above are like WebService errors.
+        );
+    }
+
+    /**
+     * Given an error returned by a WS call, check if the error is a token expired error.
+     *
+     * @param error Error to check.
+     * @returns Whether the error is a token expired error.
+     */
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    static isExpiredTokenError(error: any): boolean {
+        return error.errorcode === 'invalidtoken' ||
+            (error.errorcode === 'accessexception' && error.message.includes('Invalid token - token expired'));
+    }
+
 }
 
 type CoreWSErrorData = {
diff --git a/src/core/classes/sites/authenticated-site.ts b/src/core/classes/sites/authenticated-site.ts
index 3f4858920..6dd5c30fb 100644
--- a/src/core/classes/sites/authenticated-site.ts
+++ b/src/core/classes/sites/authenticated-site.ts
@@ -642,7 +642,7 @@ export class CoreAuthenticatedSite extends CoreUnauthenticatedSite {
         } catch (error) {
             let useSilentError = false;
 
-            if (CoreUtils.isExpiredTokenError(error)) {
+            if (CoreWSError.isExpiredTokenError(error)) {
                 // Session expired, trigger event.
                 this.triggerSiteEvent(CoreEvents.SESSION_EXPIRED, {});
                 // Change error message. Try to get data from cache, the event will handle the error.
@@ -719,7 +719,7 @@ export class CoreAuthenticatedSite extends CoreUnauthenticatedSite {
                 throw new CoreWSError(error);
             }
 
-            if (preSets.deleteCacheIfWSError && CoreUtils.isWebServiceError(error)) {
+            if (preSets.deleteCacheIfWSError && CoreWSError.isWebServiceError(error)) {
                 // Delete the cache entry and return the entry. Don't block the user with the delete.
                 CorePromiseUtils.ignoreErrors(this.deleteFromCache(method, data, preSets));
 
@@ -785,7 +785,7 @@ export class CoreAuthenticatedSite extends CoreUnauthenticatedSite {
         try {
             return await this.callOrEnqueueRequest<T>(method, data, preSets, wsPreSets);
         } catch (error) {
-            if (CoreUtils.isExpiredTokenError(error)) {
+            if (CoreWSError.isExpiredTokenError(error)) {
                 if (initialToken !== this.token) {
                     // Token has changed, retry with the new token.
                     wsPreSets.wsToken = this.token ?? '';
diff --git a/src/core/directives/format-text.ts b/src/core/directives/format-text.ts
index 47896df27..7257beb71 100644
--- a/src/core/directives/format-text.ts
+++ b/src/core/directives/format-text.ts
@@ -32,7 +32,7 @@ import { CoreSites } from '@services/sites';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreIframeUtils, CoreIframeUtilsProvider } from '@services/utils/iframe';
 import { CoreText } from '@singletons/text';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreErrorHelper } from '@services/error-helper';
 import { CoreSite } from '@classes/sites/site';
 import { NgZone, Translate } from '@singletons';
 import { CoreExternalContentDirective } from './external-content';
@@ -627,7 +627,7 @@ export class CoreFormatTextDirective implements OnChanges, OnDestroy, AsyncDirec
         }
 
         // Run asynchronous operations in the background to avoid blocking rendering.
-        Promise.all(promises).catch(error => CoreUtils.logUnhandledError('Error treating format-text elements', error));
+        Promise.all(promises).catch(error => CoreErrorHelper.logUnhandledError('Error treating format-text elements', error));
 
         return [
             ...videoControllers,
diff --git a/src/core/features/comments/services/comments-sync.ts b/src/core/features/comments/services/comments-sync.ts
index d7e5df636..d6f933694 100644
--- a/src/core/features/comments/services/comments-sync.ts
+++ b/src/core/features/comments/services/comments-sync.ts
@@ -20,7 +20,7 @@ import { makeSingleton, Translate } from '@singletons';
 import { CoreCommentsOffline } from './comments-offline';
 import { CoreSites } from '@services/sites';
 import { CoreNetwork } from '@services/network';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCommentsDBRecord, CoreCommentsDeletedDBRecord } from './database/comments';
 import { CoreSyncResult } from '@services/sync';
@@ -282,7 +282,7 @@ export class CoreCommentsSyncProvider extends CoreSyncBaseProvider<CoreCommentsS
                 CoreComments.getComments(contextLevel, instanceId, component, itemId, area, 0, siteId),
             );
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
             // It's a WebService error, this means the user cannot send comments.
                 errors.push(error.message);
             } else {
diff --git a/src/core/features/comments/services/comments.ts b/src/core/features/comments/services/comments.ts
index 73669d692..c8a431b3c 100644
--- a/src/core/features/comments/services/comments.ts
+++ b/src/core/features/comments/services/comments.ts
@@ -17,7 +17,7 @@ import { CoreError } from '@classes/errors/error';
 import { CoreSite } from '@classes/sites/site';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreWSExternalWarning } from '@services/ws';
 import { makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -105,7 +105,7 @@ export class CoreCommentsProvider {
         try {
             return await this.addCommentOnline(content, contextLevel, instanceId, component, itemId, area, siteId);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the message so don't store it.
                 throw error;
             }
@@ -294,7 +294,7 @@ export class CoreCommentsProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // It's a WebService error, the user cannot send the comment so don't store it.
                 throw error;
             }
diff --git a/src/core/features/course/services/course.ts b/src/core/features/course/services/course.ts
index 3824c19b8..6281e2009 100644
--- a/src/core/features/course/services/course.ts
+++ b/src/core/features/course/services/course.ts
@@ -1327,7 +1327,7 @@ export class CoreCourseProvider {
 
             return result;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             } else {
diff --git a/src/core/features/course/services/log-helper.ts b/src/core/features/course/services/log-helper.ts
index 20ee04f29..10a62bde6 100644
--- a/src/core/features/course/services/log-helper.ts
+++ b/src/core/features/course/services/log-helper.ts
@@ -142,7 +142,7 @@ export class CoreCourseLogHelperProvider {
         try {
             await this.logOnline(ws, data, site.getId());
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that responses cannot be submitted.
                 throw error;
             }
@@ -344,7 +344,7 @@ export class CoreCourseLogHelperProvider {
             try {
                 await this.logOnline(log.ws, data, siteId);
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     // The WebService has thrown an error, this means that responses cannot be submitted.
                     await CorePromiseUtils.ignoreErrors(this.deleteWSLogs(log.ws, data, siteId));
                 }
diff --git a/src/core/features/course/services/sync.ts b/src/core/features/course/services/sync.ts
index ec51dd5e5..84bb6da02 100644
--- a/src/core/features/course/services/sync.ts
+++ b/src/core/features/course/services/sync.ts
@@ -18,7 +18,7 @@ import { CoreSyncBaseProvider } from '@classes/base-sync';
 
 import { CoreSites } from '@services/sites';
 import { CoreNetwork } from '@services/network';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreErrorHelper } from '@services/error-helper';
 import { CoreCourseOffline } from './course-offline';
 import { CoreCourse } from './course';
@@ -212,7 +212,7 @@ export class CoreCourseSyncProvider extends CoreSyncBaseProvider<CoreCourseSyncR
 
                 await CoreCourseOffline.deleteManualCompletion(entry.cmid, siteId);
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Couldn't connect to server, reject.
                     throw error;
                 }
diff --git a/src/core/features/h5p/services/handlers/pluginfile.ts b/src/core/features/h5p/services/handlers/pluginfile.ts
index 3c3f6a513..7e04da07c 100644
--- a/src/core/features/h5p/services/handlers/pluginfile.ts
+++ b/src/core/features/h5p/services/handlers/pluginfile.ts
@@ -20,7 +20,7 @@ import { CorePluginFileDownloadableResult, CorePluginFileHandler } from '@servic
 import { CoreSites } from '@services/sites';
 import { CoreMimetypeUtils } from '@services/utils/mimetype';
 import { CoreUrl } from '@singletons/url';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreWSFile } from '@services/ws';
 import { CoreH5P } from '../h5p';
 import { Translate, makeSingleton } from '@singletons';
@@ -103,7 +103,7 @@ export class CoreH5PPluginFileHandlerService implements CorePluginFileHandler {
 
             return trustedFile.filesize || 0;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // WS returned an error, it means it cannot be downloaded.
                 return 0;
             }
diff --git a/src/core/features/pushnotifications/services/pushnotifications.ts b/src/core/features/pushnotifications/services/pushnotifications.ts
index 4b151608a..3550f9b6d 100644
--- a/src/core/features/pushnotifications/services/pushnotifications.ts
+++ b/src/core/features/pushnotifications/services/pushnotifications.ts
@@ -57,6 +57,7 @@ import { CoreNavigator } from '@services/navigator';
 import { CoreWait } from '@singletons/wait';
 import { MAIN_MENU_HANDLER_BADGE_UPDATED_EVENT } from '@features/mainmenu/constants';
 import { CorePromiseUtils } from '@singletons/promise-utils';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Service to handle push notifications.
@@ -578,7 +579,7 @@ export class CorePushNotificationsProvider {
         try {
             response = await site.write<CoreUserRemoveUserDeviceWSResponse>('core_user_remove_user_device', data);
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error) || CoreUtils.isExpiredTokenError(error)) {
+            if (CoreWSError.isWebServiceError(error) || CoreWSError.isExpiredTokenError(error)) {
                 // Cannot unregister. Don't try again.
                 await CorePromiseUtils.ignoreErrors(this.pendingUnregistersTable.delete({
                     token: site.getToken(),
diff --git a/src/core/features/rating/services/rating-sync.ts b/src/core/features/rating/services/rating-sync.ts
index 9e51a576f..0a9e5e54d 100644
--- a/src/core/features/rating/services/rating-sync.ts
+++ b/src/core/features/rating/services/rating-sync.ts
@@ -19,7 +19,7 @@ import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
 import { CoreErrorHelper } from '@services/error-helper';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { CoreRating } from './rating';
@@ -222,7 +222,7 @@ export class CoreRatingSyncProvider extends CoreSyncBaseProvider<CoreRatingSyncI
                     siteId,
                 );
             } catch (error) {
-                if (!CoreUtils.isWebServiceError(error)) {
+                if (!CoreWSError.isWebServiceError(error)) {
                     // Couldn't connect to server, reject.
                     throw error;
                 }
diff --git a/src/core/features/rating/services/rating.ts b/src/core/features/rating/services/rating.ts
index 020530845..9187a49a1 100644
--- a/src/core/features/rating/services/rating.ts
+++ b/src/core/features/rating/services/rating.ts
@@ -24,6 +24,7 @@ import { makeSingleton } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { CoreRatingOffline } from './rating-offline';
 import { CoreSiteWSPreSets } from '@classes/sites/authenticated-site';
+import { CoreWSError } from '@classes/errors/wserror';
 
 const ROOT_CACHE_KEY = 'CoreRating:';
 
@@ -128,7 +129,7 @@ export class CoreRatingProvider {
 
             return response;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error or offline not supported, reject.
                 return Promise.reject(error);
             }
diff --git a/src/core/features/user/services/user-sync.ts b/src/core/features/user/services/user-sync.ts
index 4b2a76b3a..d7836502d 100644
--- a/src/core/features/user/services/user-sync.ts
+++ b/src/core/features/user/services/user-sync.ts
@@ -16,7 +16,7 @@ import { Injectable } from '@angular/core';
 
 import { CoreSites } from '@services/sites';
 import { CoreErrorHelper } from '@services/error-helper';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreSyncBaseProvider } from '@classes/base-sync';
 import { makeSingleton } from '@singletons';
 import { CoreUserOffline } from './user-offline';
@@ -89,7 +89,7 @@ export class CoreUserSyncProvider extends CoreSyncBaseProvider<string[]> {
             try {
                 await CoreUser.setUserPreference(preference.name, preference.value, siteId);
             } catch (error) {
-                if (CoreUtils.isWebServiceError(error)) {
+                if (CoreWSError.isWebServiceError(error)) {
                     const warning = CoreErrorHelper.getErrorMessageFromError(error);
                     if (warning) {
                         warnings.push(warning);
diff --git a/src/core/features/xapi/services/xapi.ts b/src/core/features/xapi/services/xapi.ts
index 553b5b803..4167abd71 100644
--- a/src/core/features/xapi/services/xapi.ts
+++ b/src/core/features/xapi/services/xapi.ts
@@ -16,7 +16,7 @@ import { Injectable } from '@angular/core';
 
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
-import { CoreUtils } from '@services/utils/utils';
+import { CoreWSError } from '@classes/errors/wserror';
 import { CoreSite } from '@classes/sites/site';
 import { CoreXAPIOffline, CoreXAPIOfflineSaveStatementsOptions } from './offline';
 import { makeSingleton } from '@singletons';
@@ -121,7 +121,7 @@ export class CoreXAPIProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that the state cannot be deleted.
                 throw error;
             }
@@ -347,7 +347,7 @@ export class CoreXAPIProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that statements cannot be submitted.
                 throw error;
             } else {
@@ -421,7 +421,7 @@ export class CoreXAPIProvider {
 
             return true;
         } catch (error) {
-            if (CoreUtils.isWebServiceError(error)) {
+            if (CoreWSError.isWebServiceError(error)) {
                 // The WebService has thrown an error, this means that state cannot be submitted.
                 throw error;
             }
diff --git a/src/core/services/error-helper.ts b/src/core/services/error-helper.ts
index daadb2382..3d82a7672 100644
--- a/src/core/services/error-helper.ts
+++ b/src/core/services/error-helper.ts
@@ -16,6 +16,7 @@ import { Injectable } from '@angular/core';
 import { CoreAnyError, CoreError } from '@classes/errors/error';
 import { makeSingleton, Translate } from '@singletons';
 import { AlertButton } from '@ionic/angular';
+import { CoreWSError } from '@classes/errors/wserror';
 
 /**
  * Provider to provide some helper functions regarding files and packages.
@@ -23,6 +24,24 @@ import { AlertButton } from '@ionic/angular';
 @Injectable({ providedIn: 'root' })
 export class CoreErrorHelperService {
 
+    /**
+     * Given an error, add an extra warning to the error message and return the new error message.
+     *
+     * @param error Error object or message.
+     * @param defaultError Message to show if the error is not a string.
+     * @returns New error message.
+     */
+    addDataNotDownloadedError(error: Error | string, defaultError?: string): string {
+        const errorMessage = CoreErrorHelper.getErrorMessageFromError(error) || defaultError || '';
+
+        if (CoreWSError.isWebServiceError(error)) {
+            return errorMessage;
+        }
+
+        // Local error. Add an extra warning.
+        return errorMessage + '<br><br>' + Translate.instant('core.errorsomedatanotdownloaded');
+    }
+
     /**
      * Add some text to an error message.
      *
@@ -158,6 +177,17 @@ export class CoreErrorHelperService {
         return element?.innerText.trim() ?? '';
     }
 
+    /**
+     * Log an unhandled error.
+     *
+     * @param message Message to contextualize the error.
+     * @param error Error to log.
+     */
+    logUnhandledError(message: string, error: unknown): void {
+       // eslint-disable-next-line no-console
+       console.error('Unhandled error: '+message, error);
+    }
+
 }
 export const CoreErrorHelper = makeSingleton(CoreErrorHelperService);
 
diff --git a/src/core/services/urlschemes.ts b/src/core/services/urlschemes.ts
index 35c419d95..f7131a788 100644
--- a/src/core/services/urlschemes.ts
+++ b/src/core/services/urlschemes.ts
@@ -29,7 +29,6 @@ import { CoreSiteCheckResponse, CoreSites } from './sites';
 import { CoreDomUtils } from './utils/dom';
 import { CoreErrorHelper, CoreErrorObject } from './error-helper';
 import { CoreUrl } from '@singletons/url';
-import { CoreUtils } from './utils/utils';
 import { CoreLoadings } from './loadings';
 
 /*
@@ -494,7 +493,7 @@ export class CoreCustomURLSchemesProvider {
     treatHandleCustomURLError(error: CoreCustomURLSchemesHandleError): void {
         if (error.error == 'Duplicated') {
             // Duplicated request
-        } else if (CoreUtils.isWebServiceError(error.error) && error.data && error.data.isSSOToken) {
+        } else if (CoreWSError.isWebServiceError(error.error) && error.data && error.data.isSSOToken) {
             // An error occurred, display the error and logout the user.
             CoreLoginHelper.treatUserTokenError(error.data.siteUrl, <CoreWSError> error.error);
             CoreSites.logout();
diff --git a/src/core/services/utils/utils.ts b/src/core/services/utils/utils.ts
index ddf5aa58f..aef33eabe 100644
--- a/src/core/services/utils/utils.ts
+++ b/src/core/services/utils/utils.ts
@@ -62,16 +62,10 @@ export class CoreUtilsProvider {
      * @param error Error object or message.
      * @param defaultError Message to show if the error is not a string.
      * @returns New error message.
+     * @deprecated since 5.0. Use CoreErrorHelper.addDataNotDownloadedError instead.
      */
     addDataNotDownloadedError(error: Error | string, defaultError?: string): string {
-        const errorMessage = CoreErrorHelper.getErrorMessageFromError(error) || defaultError || '';
-
-        if (this.isWebServiceError(error)) {
-            return errorMessage;
-        }
-
-        // Local error. Add an extra warning.
-        return errorMessage + '<br><br>' + Translate.instant('core.errorsomedatanotdownloaded');
+        return CoreErrorHelper.addDataNotDownloadedError(error, defaultError);
     }
 
     /**
@@ -123,9 +117,10 @@ export class CoreUtilsProvider {
      *
      * @param message Message to contextualize the error.
      * @param error Error to log.
+     * @deprecated since 5.0. Use CoreErrorHelper.logUnhandledError instead.
      */
     logUnhandledError(message: string, error: unknown): void {
-        this.logger.error(message, error);
+        CoreErrorHelper.logUnhandledError(message, error);
     }
 
     /**
@@ -828,6 +823,7 @@ export class CoreUtilsProvider {
      *
      * @param error Error to check.
      * @returns Whether the error was returned by the WebService.
+     * @deprecated since 5.0. Use CoreWSError.isWebServiceError instead.
      */
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     isWebServiceError(error: any): boolean {
@@ -838,6 +834,7 @@ export class CoreUtilsProvider {
                 error.errorcode != 'forcepasswordchangenotice' && error.errorcode != 'usernotfullysetup' &&
                 error.errorcode != 'sitepolicynotagreed' && error.errorcode != 'sitemaintenance' &&
                 error.errorcode != 'wsaccessusersuspended' && error.errorcode != 'wsaccessuserdeleted' &&
+                // eslint-disable-next-line deprecation/deprecation
                 !this.isExpiredTokenError(error)
             ) ||
             error.status && error.status >= 400 // CoreHttpError, assume status 400 and above are like WebService errors.
@@ -849,6 +846,7 @@ export class CoreUtilsProvider {
      *
      * @param error Error to check.
      * @returns Whether the error is a token expired error.
+     * @deprecated since 5.0. Use CoreWSError.isExpiredTokenError instead.
      */
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     isExpiredTokenError(error: any): boolean {