diff --git a/src/addons/mod/assign/components/index/addon-mod-assign-index.html b/src/addons/mod/assign/components/index/addon-mod-assign-index.html
index 8ae559539..1f7633bd4 100644
--- a/src/addons/mod/assign/components/index/addon-mod-assign-index.html
+++ b/src/addons/mod/assign/components/index/addon-mod-assign-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -122,10 +122,11 @@
     </ng-container>
 
     <!-- If it's a student, display his submission. -->
-    <addon-mod-assign-submission *ngIf="loaded && !canViewAllSubmissions && canViewOwnSubmission" [courseId]="courseId"
+    <addon-mod-assign-submission *ngIf="!showLoading && !canViewAllSubmissions && canViewOwnSubmission" [courseId]="courseId"
         [moduleId]="module.id">
     </addon-mod-assign-submission>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/assign/pages/edit/edit.ts b/src/addons/mod/assign/pages/edit/edit.ts
index 01ddb7499..6e0f06b8d 100644
--- a/src/addons/mod/assign/pages/edit/edit.ts
+++ b/src/addons/mod/assign/pages/edit/edit.ts
@@ -36,6 +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';
 
 /**
  * Page that allows adding or editing an assigment submission.
@@ -255,7 +256,7 @@ export class AddonModAssignEditPage implements OnInit, OnDestroy, CanLeave {
                 this.hasOffline,
             );
         } catch (error) {
-            if (this.allowOffline && !this.saveOffline) {
+            if (this.allowOffline && !this.saveOffline && !CoreUtils.isWebServiceError(error)) {
                 // Cannot submit in online, prepare for offline usage.
                 this.saveOffline = true;
 
diff --git a/src/addons/mod/assign/pages/index/index.html b/src/addons/mod/assign/pages/index/index.html
index 0d424c637..71f69b398 100644
--- a/src/addons/mod/assign/pages/index/index.html
+++ b/src/addons/mod/assign/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/assign/services/assign-helper.ts b/src/addons/mod/assign/services/assign-helper.ts
index cb062c240..c3f948527 100644
--- a/src/addons/mod/assign/services/assign-helper.ts
+++ b/src/addons/mod/assign/services/assign-helper.ts
@@ -15,7 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreFileUploader, CoreFileUploaderStoreFilesResult } from '@features/fileuploader/services/fileuploader';
 import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
-import { FileEntry } from '@ionic-native/file/ngx';
+import { FileEntry, DirectoryEntry } from '@ionic-native/file/ngx';
 import {
     AddonModAssignProvider,
     AddonModAssignAssign,
diff --git a/src/addons/mod/assign/submission/file/services/handler.ts b/src/addons/mod/assign/submission/file/services/handler.ts
index f1b52ea2f..7c684ea89 100644
--- a/src/addons/mod/assign/submission/file/services/handler.ts
+++ b/src/addons/mod/assign/submission/file/services/handler.ts
@@ -187,7 +187,8 @@ export class AddonModAssignSubmissionFileHandlerService implements AddonModAssig
         plugin: AddonModAssignPlugin,
     ): Promise<number> {
         // Check if there's any change.
-        if (this.hasDataChanged(assign, submission, plugin)) {
+        const hasChanged = await this.hasDataChanged(assign, submission, plugin);
+        if (hasChanged) {
             const files = CoreFileSession.getFiles(AddonModAssignProvider.COMPONENT, assign.id);
 
             return CoreFileHelper.getTotalFilesSize(files);
diff --git a/src/addons/mod/bigbluebuttonbn/components/index/index.html b/src/addons/mod/bigbluebuttonbn/components/index/index.html
index 39f7bd548..911bc6123 100644
--- a/src/addons/mod/bigbluebuttonbn/components/index/index.html
+++ b/src/addons/mod/bigbluebuttonbn/components/index/index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-page">
+<core-loading [hideUntil]="!showLoading" class="safe-area-page">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -112,5 +112,6 @@
     </ng-container>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/bigbluebuttonbn/components/index/index.ts b/src/addons/mod/bigbluebuttonbn/components/index/index.ts
index 8d85abf94..5f1e648cb 100644
--- a/src/addons/mod/bigbluebuttonbn/components/index/index.ts
+++ b/src/addons/mod/bigbluebuttonbn/components/index/index.ts
@@ -115,14 +115,14 @@ export class AddonModBBBIndexComponent extends CoreCourseModuleMainActivityCompo
             return;
         }
 
-        this.loaded = false;
+        this.showLoading = true;
 
         try {
             await AddonModBBB.invalidateAllGroupsMeetingInfo(this.bbb.id);
 
             await this.fetchMeetingInfo();
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
@@ -148,14 +148,14 @@ export class AddonModBBBIndexComponent extends CoreCourseModuleMainActivityCompo
      * @return Promise resolved when done.
      */
     async groupChanged(): Promise<void> {
-        this.loaded = false;
+        this.showLoading = true;
 
         try {
             await this.fetchMeetingInfo();
         } catch (error) {
             CoreDomUtils.showErrorModal(error);
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
diff --git a/src/addons/mod/bigbluebuttonbn/pages/index/index.html b/src/addons/mod/bigbluebuttonbn/pages/index/index.html
index 5d8e5197e..f6e0e524e 100644
--- a/src/addons/mod/bigbluebuttonbn/pages/index/index.html
+++ b/src/addons/mod/bigbluebuttonbn/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/book/components/index/addon-mod-book-index.html b/src/addons/mod/book/components/index/addon-mod-book-index.html
index f8d3545b6..410dd43cc 100644
--- a/src/addons/mod/book/components/index/addon-mod-book-index.html
+++ b/src/addons/mod/book/components/index/addon-mod-book-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -41,5 +41,6 @@
 
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/book/pages/index/index.html b/src/addons/mod/book/pages/index/index.html
index b09bfab96..fb3db333b 100644
--- a/src/addons/mod/book/pages/index/index.html
+++ b/src/addons/mod/book/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/chat/components/index/addon-mod-chat-index.html b/src/addons/mod/chat/components/index/addon-mod-chat-index.html
index 47f13bd8c..7296cddb5 100644
--- a/src/addons/mod/chat/components/index/addon-mod-chat-index.html
+++ b/src/addons/mod/chat/components/index/addon-mod-chat-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -30,5 +30,6 @@
     </ng-container>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/chat/pages/index/index.html b/src/addons/mod/chat/pages/index/index.html
index ed096fe29..bc5f254eb 100644
--- a/src/addons/mod/chat/pages/index/index.html
+++ b/src/addons/mod/chat/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/choice/components/index/addon-mod-choice-index.html b/src/addons/mod/choice/components/index/addon-mod-choice-index.html
index e29970de6..1eebfa01c 100644
--- a/src/addons/mod/choice/components/index/addon-mod-choice-index.html
+++ b/src/addons/mod/choice/components/index/addon-mod-choice-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -135,7 +135,8 @@
     </ion-card>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
 
 <!-- Template to render a choice option label. -->
diff --git a/src/addons/mod/choice/pages/index/index.html b/src/addons/mod/choice/pages/index/index.html
index 7c56322d2..b5a04c2a6 100644
--- a/src/addons/mod/choice/pages/index/index.html
+++ b/src/addons/mod/choice/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/data/components/index/addon-mod-data-index.html b/src/addons/mod/data/components/index/addon-mod-data-index.html
index 3a8aa7713..6f15f5132 100644
--- a/src/addons/mod/data/components/index/addon-mod-data-index.html
+++ b/src/addons/mod/data/components/index/addon-mod-data-index.html
@@ -18,7 +18,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -120,7 +120,8 @@
 
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
 
 <ion-fab slot="fixed" core-fab vertical="bottom" horizontal="end" *ngIf="canAdd">
diff --git a/src/addons/mod/data/components/index/index.ts b/src/addons/mod/data/components/index/index.ts
index 9bdb523fe..2c367fa48 100644
--- a/src/addons/mod/data/components/index/index.ts
+++ b/src/addons/mod/data/components/index/index.ts
@@ -133,7 +133,7 @@ export class AddonModDataIndexComponent extends CoreCourseModuleMainActivityComp
         // Refresh entries on change.
         this.entryChangedObserver = CoreEvents.on(AddonModDataProvider.ENTRY_CHANGED, (eventData) => {
             if (this.database?.id == eventData.dataId) {
-                this.loaded = false;
+                this.showLoading = true;
 
                 return this.loadContent(true);
             }
@@ -191,7 +191,7 @@ export class AddonModDataIndexComponent extends CoreCourseModuleMainActivityComp
      */
     protected isRefreshSyncNeeded(syncEventData: AddonModDataAutoSyncData): boolean {
         if (this.database && syncEventData.dataId == this.database.id && syncEventData.entryId === undefined) {
-            this.loaded = false;
+            this.showLoading = true;
             // Refresh the data.
             this.content?.scrollToTop();
 
@@ -404,7 +404,7 @@ export class AddonModDataIndexComponent extends CoreCourseModuleMainActivityComp
      * @return Resolved when done.
      */
     async searchEntries(page: number): Promise<void> {
-        this.loaded = false;
+        this.showLoading = true;
         this.search.page = page;
 
         try {
@@ -414,7 +414,7 @@ export class AddonModDataIndexComponent extends CoreCourseModuleMainActivityComp
         } catch (error) {
             CoreDomUtils.showErrorModalDefault(error, 'core.course.errorgetmodule', true);
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
diff --git a/src/addons/mod/data/pages/edit/edit.ts b/src/addons/mod/data/pages/edit/edit.ts
index dc307eaa2..e6878e177 100644
--- a/src/addons/mod/data/pages/edit/edit.ts
+++ b/src/addons/mod/data/pages/edit/edit.ts
@@ -266,9 +266,10 @@ export class AddonModDataEditPage implements OnInit {
                         this.offline,
                     );
                 } catch (error) {
-                    if (this.offline) {
+                    if (this.offline || CoreUtils.isWebServiceError(error)) {
                         throw error;
                     }
+
                     // Cannot submit in online, prepare for offline usage.
                     this.offline = true;
 
diff --git a/src/addons/mod/data/pages/index/index.html b/src/addons/mod/data/pages/index/index.html
index 46e4a1dd9..ff9ed701e 100644
--- a/src/addons/mod/data/pages/index/index.html
+++ b/src/addons/mod/data/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/feedback/components/index/addon-mod-feedback-index.html b/src/addons/mod/feedback/components/index/addon-mod-feedback-index.html
index e336d35e1..3abdff768 100644
--- a/src/addons/mod/feedback/components/index/addon-mod-feedback-index.html
+++ b/src/addons/mod/feedback/components/index/addon-mod-feedback-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -35,7 +35,8 @@
     </core-tabs>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
 
 <ng-template #basicInfo>
diff --git a/src/addons/mod/feedback/components/index/index.ts b/src/addons/mod/feedback/components/index/index.ts
index 255b0e6ce..e31b5f529 100644
--- a/src/addons/mod/feedback/components/index/index.ts
+++ b/src/addons/mod/feedback/components/index/index.ts
@@ -97,7 +97,7 @@ export class AddonModFeedbackIndexComponent extends CoreCourseModuleMainActivity
 
             this.tabsLoaded.analysis = false;
             this.tabsLoaded.overview = false;
-            this.loaded = false;
+            this.showLoading = true;
 
             // Prefetch data if needed.
             if (!data.offline && this.isPrefetched()) {
diff --git a/src/addons/mod/feedback/pages/index/index.html b/src/addons/mod/feedback/pages/index/index.html
index fa031ccc7..6996000e4 100644
--- a/src/addons/mod/feedback/pages/index/index.html
+++ b/src/addons/mod/feedback/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/folder/components/index/addon-mod-folder-index.html b/src/addons/mod/folder/components/index/addon-mod-folder-index.html
index b01b72741..82cb66284 100644
--- a/src/addons/mod/folder/components/index/addon-mod-folder-index.html
+++ b/src/addons/mod/folder/components/index/addon-mod-folder-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info *ngIf="!subfolder" [module]="module" [description]="description" [component]="component"
@@ -32,5 +32,6 @@
 
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/folder/components/index/index.ts b/src/addons/mod/folder/components/index/index.ts
index 562a2824e..fcfa675c7 100644
--- a/src/addons/mod/folder/components/index/index.ts
+++ b/src/addons/mod/folder/components/index/index.ts
@@ -55,7 +55,7 @@ export class AddonModFolderIndexComponent extends CoreCourseModuleMainResourceCo
             this.description = this.folderInstance ? this.folderInstance.intro : this.module.description;
             this.contents = this.subfolder;
 
-            this.loaded = true;
+            this.showLoading = false;
 
             return;
         }
@@ -70,7 +70,7 @@ export class AddonModFolderIndexComponent extends CoreCourseModuleMainResourceCo
                 // Ignore errors.
             }
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
diff --git a/src/addons/mod/folder/pages/index/index.html b/src/addons/mod/folder/pages/index/index.html
index 442b976ec..b83a186f5 100644
--- a/src/addons/mod/folder/pages/index/index.html
+++ b/src/addons/mod/folder/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="subfolder || !activityComponent?.loaded"
+    <ion-refresher slot="fixed" [disabled]="subfolder || activityComponent?.showLoading"
         (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
diff --git a/src/addons/mod/forum/components/index/index.html b/src/addons/mod/forum/components/index/index.html
index 35776441c..61ff3501f 100644
--- a/src/addons/mod/forum/components/index/index.html
+++ b/src/addons/mod/forum/components/index/index.html
@@ -7,11 +7,11 @@
 
 <!-- Content. -->
 <core-split-view>
-    <ion-refresher slot="fixed" [disabled]="discussions && !discussions.loaded" (ionRefresh)="doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="showLoading || (discussions && !discussions.loaded)" (ionRefresh)="doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
-    <core-loading [hideUntil]="discussions && discussions.loaded">
+    <core-loading [hideUntil]="!showLoading && discussions && discussions.loaded">
         <!-- Activity info. -->
         <core-course-module-info [module]="module" [description]="forum && forum.type != 'single' && description" [component]="component"
             [componentId]="componentId" [courseId]="courseId" [hasDataToSync]="hasOffline || hasOfflineRatings">
@@ -114,7 +114,7 @@
         </ng-container>
     </core-loading>
 
-    <core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module"
+    <core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
         (completionChanged)="onCompletionChange()">
     </core-course-module-navigation>
 
diff --git a/src/addons/mod/forum/components/post/post.ts b/src/addons/mod/forum/components/post/post.ts
index 2a2cf19ed..cfd60670f 100644
--- a/src/addons/mod/forum/components/post/post.ts
+++ b/src/addons/mod/forum/components/post/post.ts
@@ -364,7 +364,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
                     );
                 } catch (error) {
                     // Cannot upload them in online, save them in offline.
-                    if (!this.forum.id || isEditOnline) {
+                    if (!this.forum.id || isEditOnline || CoreUtils.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 0519efe28..47c2bd0cc 100644
--- a/src/addons/mod/forum/services/forum-helper.ts
+++ b/src/addons/mod/forum/services/forum-helper.ts
@@ -106,6 +106,10 @@ export class AddonModForumHelperProvider {
             try {
                 await Promise.all(promises);
             } catch (error) {
+                if (CoreUtils.isWebServiceError(error)) {
+                    throw error;
+                }
+
                 // Cannot upload them in online, save them in offline.
                 saveOffline = true;
 
diff --git a/src/addons/mod/glossary/components/index/addon-mod-glossary-index.html b/src/addons/mod/glossary/components/index/addon-mod-glossary-index.html
index 524abb9b1..c973a95a3 100644
--- a/src/addons/mod/glossary/components/index/addon-mod-glossary-index.html
+++ b/src/addons/mod/glossary/components/index/addon-mod-glossary-index.html
@@ -16,7 +16,7 @@
 
 <!-- Content. -->
 <core-split-view>
-    <ion-refresher slot="fixed" [disabled]="!loaded" (ionRefresh)="doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="showLoading" (ionRefresh)="doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
@@ -24,7 +24,7 @@
         [autoFocus]="true" [lengthCheck]="2" (onClear)="toggleSearch()" searchArea="AddonModGlossary-{{module.id}}">
     </core-search-box>
 
-    <core-loading [hideUntil]="loaded">
+    <core-loading [hideUntil]="!showLoading">
         <!-- Activity info. -->
         <core-course-module-info *ngIf="!isSearch" [module]="module" [description]="description" [component]="component"
             [componentId]="componentId" [courseId]="courseId" [hasDataToSync]="hasOffline || hasOfflineRatings">
@@ -72,7 +72,7 @@
         </core-infinite-loading>
     </core-loading>
 
-    <core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module"
+    <core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
         (completionChanged)="onCompletionChange()">
     </core-course-module-navigation>
 
diff --git a/src/addons/mod/glossary/components/index/index.ts b/src/addons/mod/glossary/components/index/index.ts
index cbcc5aa89..4e483a919 100644
--- a/src/addons/mod/glossary/components/index/index.ts
+++ b/src/addons/mod/glossary/components/index/index.ts
@@ -393,7 +393,7 @@ export class AddonModGlossaryIndexComponent extends CoreCourseModuleMainActivity
         this.loadingMessage = Translate.instant('core.loading');
         this.content?.scrollToTop();
         this.switchMode(mode);
-        this.loaded = false;
+        this.showLoading = true;
         this.loadContent();
     }
 
@@ -411,7 +411,7 @@ export class AddonModGlossaryIndexComponent extends CoreCourseModuleMainActivity
      */
     search(query: string): void {
         this.loadingMessage = Translate.instant('core.searching');
-        this.loaded = false;
+        this.showLoading = true;
 
         this.entries?.getSource().search(query);
         this.loadContent();
diff --git a/src/addons/mod/glossary/pages/edit/edit.ts b/src/addons/mod/glossary/pages/edit/edit.ts
index 2edc0d440..127a5ea4a 100644
--- a/src/addons/mod/glossary/pages/edit/edit.ts
+++ b/src/addons/mod/glossary/pages/edit/edit.ts
@@ -25,6 +25,7 @@ import { CoreNavigator } from '@services/navigator';
 import { CoreSites } from '@services/sites';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreTextUtils } from '@services/utils/text';
+import { CoreUtils } from '@services/utils/utils';
 import { Translate } from '@singletons';
 import { CoreEventObserver, CoreEvents } from '@singletons/events';
 import { CoreForms } from '@singletons/form';
@@ -392,7 +393,11 @@ export class AddonModGlossaryEditPage implements OnInit, OnDestroy, CanLeave {
                 saveOffline: false,
                 attachmentsResult,
             };
-        } catch {
+        } catch (error) {
+            if (CoreUtils.isWebServiceError(error)) {
+                throw error;
+            }
+
             // Cannot upload them in online, save them in offline.
             const attachmentsResult = await AddonModGlossaryHelper.storeFiles(
                 this.glossary.id,
diff --git a/src/addons/mod/h5pactivity/components/index/addon-mod-h5pactivity-index.html b/src/addons/mod/h5pactivity/components/index/addon-mod-h5pactivity-index.html
index 039f30ce2..deed6960a 100644
--- a/src/addons/mod/h5pactivity/components/index/addon-mod-h5pactivity-index.html
+++ b/src/addons/mod/h5pactivity/components/index/addon-mod-h5pactivity-index.html
@@ -16,7 +16,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -68,5 +68,6 @@
     </core-h5p-iframe>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/h5pactivity/pages/index/index.html b/src/addons/mod/h5pactivity/pages/index/index.html
index 6ac751048..8c2890fee 100644
--- a/src/addons/mod/h5pactivity/pages/index/index.html
+++ b/src/addons/mod/h5pactivity/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/imscp/components/index/addon-mod-imscp-index.html b/src/addons/mod/imscp/components/index/addon-mod-imscp-index.html
index d795fb3fe..a3ce89920 100644
--- a/src/addons/mod/imscp/components/index/addon-mod-imscp-index.html
+++ b/src/addons/mod/imscp/components/index/addon-mod-imscp-index.html
@@ -1,6 +1,6 @@
 <!-- Buttons to add to the header. -->
 <core-navbar-buttons slot="end">
-    <ion-button *ngIf="loaded" (click)="showToc()" aria-haspopup="true" [attr.aria-label]="'addon.mod_imscp.toc' | translate">
+    <ion-button *ngIf="!showLoading" (click)="showToc()" aria-haspopup="true" [attr.aria-label]="'addon.mod_imscp.toc' | translate">
         <ion-icon name="fas-bookmark" slot="icon-only" aria-hidden="true"></ion-icon>
     </ion-button>
 
@@ -10,7 +10,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module">
@@ -26,9 +26,10 @@
     <div class="addon-mod-imscp-container">
         <core-navigation-bar [items]="navigationItems" (action)="loadItem($event)">
         </core-navigation-bar>
-        <core-iframe *ngIf="loaded" [src]="src" [showFullscreenOnToolbar]="true" [autoFullscreenOnRotate]="true"></core-iframe>
+        <core-iframe *ngIf="!showLoading" [src]="src" [showFullscreenOnToolbar]="true" [autoFullscreenOnRotate]="true"></core-iframe>
     </div>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/lesson/components/index/addon-mod-lesson-index.html b/src/addons/mod/lesson/components/index/addon-mod-lesson-index.html
index 29a420944..d79ecd5a1 100644
--- a/src/addons/mod/lesson/components/index/addon-mod-lesson-index.html
+++ b/src/addons/mod/lesson/components/index/addon-mod-lesson-index.html
@@ -6,8 +6,8 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
-    <core-tabs [hideUntil]="loaded" [selectedIndex]="selectedTab">
+<core-loading [hideUntil]="!showLoading">
+    <core-tabs [hideUntil]="!showLoading" [selectedIndex]="selectedTab">
         <!-- Index/Preview tab. -->
         <core-tab [title]="'addon.mod_lesson.preview' | translate" (ionSelect)="indexSelected()">
             <ng-template>
@@ -279,5 +279,6 @@
     </core-tabs>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/lesson/components/index/index.ts b/src/addons/mod/lesson/components/index/index.ts
index 1a9e8b614..415bf0555 100644
--- a/src/addons/mod/lesson/components/index/index.ts
+++ b/src/addons/mod/lesson/components/index/index.ts
@@ -618,7 +618,7 @@ export class AddonModLessonIndexComponent extends CoreCourseModuleMainActivityCo
             return;
         }
 
-        this.loaded = false;
+        this.showLoading = true;
 
         try {
             await this.validatePassword(<string> password);
@@ -635,7 +635,7 @@ export class AddonModLessonIndexComponent extends CoreCourseModuleMainActivityCo
         } catch (error) {
             CoreDomUtils.showErrorModal(error);
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
 
             CoreForms.triggerFormSubmittedEvent(this.formElement, true, this.siteId);
         }
diff --git a/src/addons/mod/lesson/pages/index/index.html b/src/addons/mod/lesson/pages/index/index.html
index a6b75a913..fec01e323 100644
--- a/src/addons/mod/lesson/pages/index/index.html
+++ b/src/addons/mod/lesson/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/lti/components/index/addon-mod-lti-index.html b/src/addons/mod/lti/components/index/addon-mod-lti-index.html
index dc3b6068d..1452e0c18 100644
--- a/src/addons/mod/lti/components/index/addon-mod-lti-index.html
+++ b/src/addons/mod/lti/components/index/addon-mod-lti-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="displayDescription && description" [component]="component"
@@ -21,5 +21,6 @@
     </div>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/lti/pages/index/index.html b/src/addons/mod/lti/pages/index/index.html
index 9b7017a3f..38ce5fc89 100644
--- a/src/addons/mod/lti/pages/index/index.html
+++ b/src/addons/mod/lti/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/page/components/index/addon-mod-page-index.html b/src/addons/mod/page/components/index/addon-mod-page-index.html
index 1cfc5f303..83536200d 100644
--- a/src/addons/mod/page/components/index/addon-mod-page-index.html
+++ b/src/addons/mod/page/components/index/addon-mod-page-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="displayDescription && description" [component]="component"
@@ -32,5 +32,6 @@
 
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/page/pages/index/index.html b/src/addons/mod/page/pages/index/index.html
index cab819bed..fc6dc2f86 100644
--- a/src/addons/mod/page/pages/index/index.html
+++ b/src/addons/mod/page/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/quiz/components/index/addon-mod-quiz-index.html b/src/addons/mod/quiz/components/index/addon-mod-quiz-index.html
index 6323f3cb5..59961b31c 100644
--- a/src/addons/mod/quiz/components/index/addon-mod-quiz-index.html
+++ b/src/addons/mod/quiz/components/index/addon-mod-quiz-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -206,5 +206,6 @@
     </ion-card>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/quiz/components/index/index.ts b/src/addons/mod/quiz/components/index/index.ts
index 1f03d876e..d827022de 100644
--- a/src/addons/mod/quiz/components/index/index.ts
+++ b/src/addons/mod/quiz/components/index/index.ts
@@ -455,13 +455,13 @@ export class AddonModQuizIndexComponent extends CoreCourseModuleMainActivityComp
         }
 
         // Refresh data.
-        this.loaded = false;
+        this.showLoading = true;
         this.content?.scrollToTop();
 
         await promise;
         await CoreUtils.ignoreErrors(this.refreshContent(true));
 
-        this.loaded = true;
+        this.showLoading = false;
     }
 
     /**
@@ -547,8 +547,7 @@ export class AddonModQuizIndexComponent extends CoreCourseModuleMainActivityComp
 
         if (status == CoreConstants.DOWNLOADED && previousStatus == CoreConstants.DOWNLOADING) {
             // Quiz downloaded now, maybe a new attempt was created. Load content again.
-            this.loaded = false;
-            this.loadContent();
+            this.showLoadingAndFetch();
         }
     }
 
diff --git a/src/addons/mod/quiz/pages/index/index.html b/src/addons/mod/quiz/pages/index/index.html
index 9a58a95ff..233973f4f 100644
--- a/src/addons/mod/quiz/pages/index/index.html
+++ b/src/addons/mod/quiz/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/resource/components/index/addon-mod-resource-index.html b/src/addons/mod/resource/components/index/addon-mod-resource-index.html
index 89fbf28f7..1efbca3f9 100644
--- a/src/addons/mod/resource/components/index/addon-mod-resource-index.html
+++ b/src/addons/mod/resource/components/index/addon-mod-resource-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [courseId]="courseId" [description]="displayDescription && description"
@@ -97,5 +97,6 @@
     </ng-container>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/resource/pages/index/index.html b/src/addons/mod/resource/pages/index/index.html
index ac1c3727e..4bfe3e2a6 100644
--- a/src/addons/mod/resource/pages/index/index.html
+++ b/src/addons/mod/resource/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded || activityComponent?.mode == 'iframe'"
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading || activityComponent?.mode == 'iframe'"
         (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
diff --git a/src/addons/mod/scorm/components/index/addon-mod-scorm-index.html b/src/addons/mod/scorm/components/index/addon-mod-scorm-index.html
index 275c81125..96329ba19 100644
--- a/src/addons/mod/scorm/components/index/addon-mod-scorm-index.html
+++ b/src/addons/mod/scorm/components/index/addon-mod-scorm-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -21,7 +21,7 @@
         </ion-item>
     </ion-card>
 
-    <ng-container *ngIf="scorm && loaded && !scorm.warningMessage">
+    <ng-container *ngIf="scorm && !showLoading && !scorm.warningMessage">
         <!-- Attempts status. -->
         <ion-card *ngIf="(scorm.displayattemptstatus || offlineAttempts.length) && !skip">
             <ion-card-header class="ion-text-wrap">
@@ -217,5 +217,6 @@
     </ng-container>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/scorm/pages/index/index.html b/src/addons/mod/scorm/pages/index/index.html
index fc1e6f57f..00e1aa739 100644
--- a/src/addons/mod/scorm/pages/index/index.html
+++ b/src/addons/mod/scorm/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/survey/components/index/addon-mod-survey-index.html b/src/addons/mod/survey/components/index/addon-mod-survey-index.html
index acafdf331..8c99699fc 100644
--- a/src/addons/mod/survey/components/index/addon-mod-survey-index.html
+++ b/src/addons/mod/survey/components/index/addon-mod-survey-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded" class="safe-area-padding">
+<core-loading [hideUntil]="!showLoading" class="safe-area-padding">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="survey && !survey.surveydone && !hasOffline && description"
@@ -131,5 +131,6 @@
 
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/survey/pages/index/index.html b/src/addons/mod/survey/pages/index/index.html
index 808d88eb1..02673c75d 100644
--- a/src/addons/mod/survey/pages/index/index.html
+++ b/src/addons/mod/survey/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/url/components/index/addon-mod-url-index.html b/src/addons/mod/url/components/index/addon-mod-url-index.html
index ccf09a1a2..0153bcdf7 100644
--- a/src/addons/mod/url/components/index/addon-mod-url-index.html
+++ b/src/addons/mod/url/components/index/addon-mod-url-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="displayDescription && description" [component]="component"
@@ -46,5 +46,6 @@
     </ion-list>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
diff --git a/src/addons/mod/url/pages/index/index.html b/src/addons/mod/url/pages/index/index.html
index 45dc4198c..f940549ef 100644
--- a/src/addons/mod/url/pages/index/index.html
+++ b/src/addons/mod/url/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/addons/mod/wiki/components/index/addon-mod-wiki-index.html b/src/addons/mod/wiki/components/index/addon-mod-wiki-index.html
index 462d5a1b4..342e83895 100644
--- a/src/addons/mod/wiki/components/index/addon-mod-wiki-index.html
+++ b/src/addons/mod/wiki/components/index/addon-mod-wiki-index.html
@@ -7,7 +7,7 @@
         <ion-icon *ngIf="groupWiki" name="fas-users" aria-hidden="true"></ion-icon>
     </ion-button>
 
-    <ion-button *ngIf="loaded && currentPageObj" (click)="openMap()" [attr.aria-label]="'addon.mod_wiki.map' | translate"
+    <ion-button *ngIf="!showLoading && currentPageObj" (click)="openMap()" [attr.aria-label]="'addon.mod_wiki.map' | translate"
         aria-haspopup="true">
         <ion-icon name="fas-map" aria-hidden="true"></ion-icon>
     </ion-button>
@@ -27,7 +27,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [description]="description" [component]="component" [componentId]="componentId"
@@ -71,7 +71,8 @@
     </div>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
 
 <ion-fab slot="fixed" core-fab vertical="bottom" horizontal="end" *ngIf="canEdit">
diff --git a/src/addons/mod/wiki/pages/index/index.html b/src/addons/mod/wiki/pages/index/index.html
index a33c7c251..0c013169c 100644
--- a/src/addons/mod/wiki/pages/index/index.html
+++ b/src/addons/mod/wiki/pages/index/index.html
@@ -16,7 +16,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
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 f46b85d90..26d9b61c1 100644
--- a/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts
+++ b/src/addons/mod/workshop/components/assessment-strategy/assessment-strategy.ts
@@ -304,7 +304,11 @@ export class AddonModWorkshopAssessmentStrategyComponent implements OnInit, OnDe
                     files,
                     saveOffline,
                 );
-            } catch {
+            } catch (error) {
+                if (CoreUtils.isWebServiceError(error)) {
+                    throw error;
+                }
+
                 // Cannot upload them in online, save them in offline.
                 saveOffline = true;
                 allowOffline = true;
diff --git a/src/addons/mod/workshop/components/index/addon-mod-workshop-index.html b/src/addons/mod/workshop/components/index/addon-mod-workshop-index.html
index 9fc19b652..ebb5b73a3 100644
--- a/src/addons/mod/workshop/components/index/addon-mod-workshop-index.html
+++ b/src/addons/mod/workshop/components/index/addon-mod-workshop-index.html
@@ -6,7 +6,7 @@
 </core-navbar-buttons>
 
 <!-- Content. -->
-<core-loading [hideUntil]="loaded">
+<core-loading [hideUntil]="!showLoading">
 
     <!-- Activity info. -->
     <core-course-module-info [module]="module" [hasDataToSync]="hasOffline">
@@ -233,5 +233,6 @@
     </div>
 </core-loading>
 
-<core-course-module-navigation [hidden]="!loaded" [courseId]="courseId" [currentModule]="module" (completionChanged)="onCompletionChange()">
+<core-course-module-navigation [hidden]="showLoading" [courseId]="courseId" [currentModule]="module"
+    (completionChanged)="onCompletionChange()">
 </core-course-module-navigation>
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 aa215a1ce..23b7e7e5e 100644
--- a/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts
+++ b/src/addons/mod/workshop/pages/edit-submission/edit-submission.ts
@@ -25,6 +25,7 @@ import { CoreSites } from '@services/sites';
 import { CoreSync } from '@services/sync';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CoreTextUtils } from '@services/utils/text';
+import { CoreUtils } from '@services/utils/utils';
 import { Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
 import { CoreForms } from '@singletons/form';
@@ -349,7 +350,11 @@ export class AddonModWorkshopEditSubmissionPage implements OnInit, OnDestroy, Ca
                     inputData.attachmentfiles,
                     false,
                 );
-            } catch {
+            } catch (error) {
+                if (CoreUtils.isWebServiceError(error)) {
+                    throw error;
+                }
+
                 // Cannot upload them in online, save them in offline.
                 saveOffline = true;
                 allowOffline = true;
diff --git a/src/addons/mod/workshop/pages/index/index.html b/src/addons/mod/workshop/pages/index/index.html
index 9b639898c..c9fdc573a 100644
--- a/src/addons/mod/workshop/pages/index/index.html
+++ b/src/addons/mod/workshop/pages/index/index.html
@@ -15,7 +15,7 @@
     </ion-toolbar>
 </ion-header>
 <ion-content>
-    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+    <ion-refresher slot="fixed" [disabled]="activityComponent?.showLoading" (ionRefresh)="activityComponent?.doRefresh($event.target)">
         <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
     </ion-refresher>
 
diff --git a/src/core/classes/errors/errors.ts b/src/core/classes/errors/errors.ts
index 94b34a72f..517d91910 100644
--- a/src/core/classes/errors/errors.ts
+++ b/src/core/classes/errors/errors.ts
@@ -24,6 +24,7 @@ import { CoreCaptureError } from './captureerror';
 import { CoreNetworkError } from './network-error';
 import { CoreSiteError } from './siteerror';
 import { CoreErrorWithTitle } from './errorwithtitle';
+import { CoreHttpError } from './httperror';
 
 export const CORE_ERRORS_CLASSES: Type<unknown>[] = [
     CoreAjaxError,
@@ -36,4 +37,5 @@ export const CORE_ERRORS_CLASSES: Type<unknown>[] = [
     CoreSiteError,
     CoreWSError,
     CoreErrorWithTitle,
+    CoreHttpError,
 ];
diff --git a/src/core/classes/errors/httperror.ts b/src/core/classes/errors/httperror.ts
new file mode 100644
index 000000000..598cc4455
--- /dev/null
+++ b/src/core/classes/errors/httperror.ts
@@ -0,0 +1,30 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { CoreError } from '@classes/errors/error';
+
+/**
+ * HTTP error.
+ */
+export class CoreHttpError extends CoreError {
+
+    status: number; // HTTP status. 0 if cannot connect or similar errors.
+
+    constructor(message: string, status?: number) {
+        super(message);
+
+        this.status = status ?? 0;
+    }
+
+}
diff --git a/src/core/features/course/classes/main-activity-component.ts b/src/core/features/course/classes/main-activity-component.ts
index d0214e996..e41b66bfb 100644
--- a/src/core/features/course/classes/main-activity-component.ts
+++ b/src/core/features/course/classes/main-activity-component.ts
@@ -116,7 +116,7 @@ export class CoreCourseModuleMainActivityComponent extends CoreCourseModuleMainR
      * @return Resolved when done.
      */
     protected async showLoadingAndFetch(sync: boolean = false, showErrors: boolean = false): Promise<void> {
-        this.loaded = false;
+        this.showLoading = true;
         this.content?.scrollToTop();
 
         await this.loadContent(false, sync, showErrors);
@@ -130,7 +130,7 @@ export class CoreCourseModuleMainActivityComponent extends CoreCourseModuleMainR
      * @return Resolved when done.
      */
     protected showLoadingAndRefresh(sync: boolean = false, showErrors: boolean = false): Promise<void> {
-        this.loaded = false;
+        this.showLoading = true;
         this.content?.scrollToTop();
 
         return this.refreshContent(sync, showErrors);
@@ -177,7 +177,7 @@ export class CoreCourseModuleMainActivityComponent extends CoreCourseModuleMainR
 
             CoreDomUtils.showErrorModalDefault(error, this.fetchContentDefaultError, true);
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
diff --git a/src/core/features/course/classes/main-resource-component.ts b/src/core/features/course/classes/main-resource-component.ts
index 6536145e0..2a0eed662 100644
--- a/src/core/features/course/classes/main-resource-component.ts
+++ b/src/core/features/course/classes/main-resource-component.ts
@@ -52,7 +52,7 @@ export class CoreCourseModuleMainResourceComponent implements OnInit, OnDestroy,
     @Input() courseId!: number; // Course ID the component belongs to.
     @Output() dataRetrieved = new EventEmitter<unknown>(); // Called to notify changes the index page from the main component.
 
-    loaded = false; // If the component has been loaded.
+    showLoading = true; // Whether to show loading.
     component?: string; // Component name.
     componentId?: number; // Component ID.
     hasOffline = false; // Resources don't have any data to sync.
@@ -199,7 +199,7 @@ export class CoreCourseModuleMainResourceComponent implements OnInit, OnDestroy,
 
             CoreDomUtils.showErrorModalDefault(error, this.fetchContentDefaultError, true);
         } finally {
-            this.loaded = true;
+            this.showLoading = false;
         }
     }
 
@@ -416,12 +416,12 @@ export class CoreCourseModuleMainResourceComponent implements OnInit, OnDestroy,
         });
 
         if (data) {
-            if (this.loaded && (data.action == 'refresh' || data.action == 'sync')) {
-                this.loaded = false;
+            if (!this.showLoading && (data.action == 'refresh' || data.action == 'sync')) {
+                this.showLoading = true;
                 try {
                     await this.doRefresh(undefined, data.action == 'sync');
                 } finally {
-                    this.loaded = true;
+                    this.showLoading = false;
                 }
             }
         }
diff --git a/src/core/services/utils/text.ts b/src/core/services/utils/text.ts
index 4c6d5f307..9a091db74 100644
--- a/src/core/services/utils/text.ts
+++ b/src/core/services/utils/text.ts
@@ -530,6 +530,18 @@ export class CoreTextUtilsProvider {
         return error.message || error.error || error.content || error.body;
     }
 
+    /**
+     * Given some HTML code, return the HTML code inside <body> tags. If there are no body tags, return the whole HTML.
+     *
+     * @param html HTML text.
+     * @return Body HTML.
+     */
+    getHTMLBodyContent(html: string): string {
+        const matches = html.match(/<body>([\s\S]*)<\/body>/im);
+
+        return matches?.[1] ?? html;
+    }
+
     /**
      * Get the pluginfile URL to replace @@PLUGINFILE@@ wildcards.
      *
diff --git a/src/core/services/utils/utils.ts b/src/core/services/utils/utils.ts
index 4808ccca5..e211d3350 100644
--- a/src/core/services/utils/utils.ts
+++ b/src/core/services/utils/utils.ts
@@ -858,12 +858,17 @@ export class CoreUtilsProvider {
      */
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     isWebServiceError(error: any): boolean {
-        return error && (error.warningcode !== undefined || (error.errorcode !== undefined &&
-                error.errorcode != 'userdeleted' && error.errorcode != 'upgraderunning' &&
+        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)));
+                !this.isExpiredTokenError(error)
+            ) ||
+            error.status && error.status >= 400 // CoreHttpError, assume status 400 and above are like WebService errors.
+        );
     }
 
     /**
diff --git a/src/core/services/ws.ts b/src/core/services/ws.ts
index d1ab15a5e..866ed0724 100644
--- a/src/core/services/ws.ts
+++ b/src/core/services/ws.ts
@@ -16,7 +16,7 @@ import { Injectable } from '@angular/core';
 import { HttpResponse, HttpParams } from '@angular/common/http';
 
 import { FileEntry } from '@ionic-native/file/ngx';
-import { FileUploadOptions } from '@ionic-native/file-transfer/ngx';
+import { FileUploadOptions, FileUploadResult } from '@ionic-native/file-transfer/ngx';
 import { Md5 } from 'ts-md5/dist/md5';
 import { Observable } from 'rxjs';
 import { timeout } from 'rxjs/operators';
@@ -25,7 +25,7 @@ import { CoreNativeToAngularHttpResponse } from '@classes/native-to-angular-http
 import { CoreApp } from '@services/app';
 import { CoreFile, CoreFileFormat } from '@services/file';
 import { CoreMimetypeUtils } from '@services/utils/mimetype';
-import { CoreTextUtils } from '@services/utils/text';
+import { CoreTextErrorObject, CoreTextUtils } from '@services/utils/text';
 import { CoreUtils, PromiseDefer } from '@services/utils/utils';
 import { CoreConstants } from '@/core/constants';
 import { CoreError } from '@classes/errors/error';
@@ -38,6 +38,7 @@ import { CoreAjaxError } from '@classes/errors/ajaxerror';
 import { CoreAjaxWSError } from '@classes/errors/ajaxwserror';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreSite } from '@classes/site';
+import { CoreHttpError } from '@classes/errors/httperror';
 
 /**
  * This service allows performing WS calls and download/upload files.
@@ -693,6 +694,8 @@ export class CoreWSProvider {
                 return retryPromise;
             } else if (error.status === -2) {
                 throw new CoreError(this.getCertificateErrorMessage(error.error));
+            } else if (error.status > 0) {
+                throw this.createHttpError(error, error.status);
             }
 
             throw new CoreError(Translate.instant('core.serverconnection'));
@@ -885,51 +888,69 @@ export class CoreWSProvider {
         options.headers = {};
         options['Connection'] = 'close';
 
+        let success: FileUploadResult;
+
         try {
-            const success = await transfer.upload(filePath, uploadUrl, options, true);
-
-            // eslint-disable-next-line @typescript-eslint/no-explicit-any
-            const data = CoreTextUtils.parseJSON<any>(
-                success.response,
-                null,
-                this.logger.error.bind(this.logger, 'Error parsing response from upload', success.response),
-            );
-
-            if (data === null) {
-                throw new CoreError(Translate.instant('core.errorinvalidresponse'));
-            }
-
-            if (!data) {
-                throw new CoreError(Translate.instant('core.serverconnection'));
-            } else if (typeof data != 'object') {
-                this.logger.warn('Upload file: Response of type "' + typeof data + '" received, expecting "object"');
-
-                throw new CoreError(Translate.instant('core.errorinvalidresponse'));
-            }
-
-            if (data.exception !== undefined) {
-                throw new CoreWSError(data);
-            } else if (data.error !== undefined) {
-                throw new CoreWSError({
-                    errorcode: data.errortype,
-                    message: data.error,
-                });
-            } else if (data[0] && data[0].error !== undefined) {
-                throw new CoreWSError({
-                    errorcode: data[0].errortype,
-                    message: data[0].error,
-                });
-            }
-
-            // We uploaded only 1 file, so we only return the first file returned.
-            this.logger.debug('Successfully uploaded file', filePath);
-
-            return data[0];
+            success = await transfer.upload(filePath, uploadUrl, options, true);
         } catch (error) {
             this.logger.error('Error while uploading file', filePath, error);
 
+            throw this.createHttpError(error, error.http_status ?? 0);
+        }
+
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        const data = CoreTextUtils.parseJSON<any>(
+            success.response,
+            null,
+            this.logger.error.bind(this.logger, 'Error parsing response from upload', success.response),
+        );
+
+        if (data === null) {
             throw new CoreError(Translate.instant('core.errorinvalidresponse'));
         }
+
+        if (!data) {
+            throw new CoreError(Translate.instant('core.serverconnection'));
+        } else if (typeof data != 'object') {
+            this.logger.warn('Upload file: Response of type "' + typeof data + '" received, expecting "object"');
+
+            throw new CoreError(Translate.instant('core.errorinvalidresponse'));
+        }
+
+        if (data.exception !== undefined) {
+            throw new CoreWSError(data);
+        } else if (data.error !== undefined) {
+            throw new CoreWSError({
+                errorcode: data.errortype,
+                message: data.error,
+            });
+        } else if (data[0] && data[0].error !== undefined) {
+            throw new CoreWSError({
+                errorcode: data[0].errortype,
+                message: data[0].error,
+            });
+        }
+
+        // We uploaded only 1 file, so we only return the first file returned.
+        this.logger.debug('Successfully uploaded file', filePath);
+
+        return data[0];
+    }
+
+    /**
+     * Create a CoreHttpError based on a certain error.
+     *
+     * @param error Original error.
+     * @param status Status code (if any).
+     * @return CoreHttpError.
+     */
+    protected createHttpError(error: CoreTextErrorObject, status: number): CoreHttpError {
+        const message = CoreTextUtils.buildSeveralParagraphsMessage([
+            Translate.instant('core.cannotconnecttrouble'),
+            CoreTextUtils.getHTMLBodyContent(CoreTextUtils.getErrorMessageFromError(error) || ''),
+        ]);
+
+        return new CoreHttpError(message, status);
     }
 
     /**
diff --git a/upgrade.txt b/upgrade.txt
index ebb311bcb..e01fe0058 100644
--- a/upgrade.txt
+++ b/upgrade.txt
@@ -22,6 +22,7 @@ information provided here is intended especially for developers.
 - The parameters of the following functions in CoreCourseHelper have changed: navigateToModuleByInstance, navigateToModule, openModule.
 - fillContextMenu, expandDescription, gotoBlog, prefetch and removeFiles functions have been removed from CoreCourseModuleMainResourceComponent.
 - contextMenuPrefetch and fillContextMenu have been removed from CoreCourseHelper.
+-The variable "loaded" in CoreCourseModuleMainResourceComponent has been changed to "showLoading" to reflect its purpose better.