diff --git a/src/addons/calendar/services/calendar-sync.ts b/src/addons/calendar/services/calendar-sync.ts
index 21845fba8..cc9cb00b0 100644
--- a/src/addons/calendar/services/calendar-sync.ts
+++ b/src/addons/calendar/services/calendar-sync.ts
@@ -27,7 +27,7 @@ import {
 import { AddonCalendarOffline } from './calendar-offline';
 import { AddonCalendarHelper } from './calendar-helper';
 import { makeSingleton, Translate } from '@singletons';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import moment from 'moment-timezone';
 
@@ -301,13 +301,11 @@ export class AddonCalendarSyncProvider extends CoreSyncBaseProvider<AddonCalenda
 
 export const AddonCalendarSync = makeSingleton(AddonCalendarSyncProvider);
 
-export type AddonCalendarSyncEvents = {
-    warnings: string[];
+export type AddonCalendarSyncEvents = CoreSyncResult & {
     events: AddonCalendarEvent[];
     offlineIdMap: Record<number, number>; // Map offline ID with online ID for created events.
     deleted: number[];
     toinvalidate: AddonCalendarSyncInvalidateEvent[];
-    updated: boolean;
     source?: string; // Added on pages.
     moment?: moment.Moment; // Added on day page.
 };
diff --git a/src/addons/mod/assign/components/index/index.ts b/src/addons/mod/assign/components/index/index.ts
index 5f4640723..411090e5c 100644
--- a/src/addons/mod/assign/components/index/index.ts
+++ b/src/addons/mod/assign/components/index/index.ts
@@ -14,6 +14,7 @@
 
 import { Component, Optional, OnDestroy, OnInit, ViewChild } from '@angular/core';
 import { Params } from '@angular/router';
+import { CoreError } from '@classes/errors/error';
 import { CoreSite } from '@classes/site';
 import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
 import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
@@ -314,11 +315,7 @@ export class AddonModAssignIndexComponent extends CoreCourseModuleMainActivityCo
     /**
      * @inheritdoc
      */
-    protected hasSyncSucceed(result?: AddonModAssignSyncResult): boolean {
-        if (!result) {
-            return false;
-        }
-
+    protected hasSyncSucceed(result: AddonModAssignSyncResult): boolean {
         if (result.updated) {
             this.submissionComponent?.invalidateAndRefresh(false);
         }
@@ -384,9 +381,9 @@ export class AddonModAssignIndexComponent extends CoreCourseModuleMainActivityCo
     /**
      * @inheritdoc
      */
-    protected async sync(): Promise<AddonModAssignSyncResult | void> {
+    protected async sync(): Promise<AddonModAssignSyncResult> {
         if (!this.assign) {
-            return;
+            throw new CoreError('Cannot sync without a assign.');
         }
 
         return AddonModAssignSync.syncAssign(this.assign.id);
diff --git a/src/addons/mod/assign/services/assign-sync.ts b/src/addons/mod/assign/services/assign-sync.ts
index 3a04878b1..1c5ced9cf 100644
--- a/src/addons/mod/assign/services/assign-sync.ts
+++ b/src/addons/mod/assign/services/assign-sync.ts
@@ -32,7 +32,7 @@ import {
     AddonModAssignSubmissionsDBRecordFormatted,
     AddonModAssignSubmissionsGradingDBRecordFormatted,
 } from './assign-offline';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreUtils } from '@services/utils/utils';
 import { CoreNetwork } from '@services/network';
@@ -530,9 +530,7 @@ export const AddonModAssignSync = makeSingleton(AddonModAssignSyncProvider);
 /**
  * Data returned by a assign sync.
  */
-export type AddonModAssignSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
+export type AddonModAssignSyncResult = CoreSyncResult & {
     courseId?: number; // Course the assign belongs to (if known).
     gradesBlocked: number[]; // Whether some grade couldn't be synced because it was blocked. UserId fields of the blocked grade.
 };
diff --git a/src/addons/mod/choice/components/index/index.ts b/src/addons/mod/choice/components/index/index.ts
index 91b25b58b..d4f7e039c 100644
--- a/src/addons/mod/choice/components/index/index.ts
+++ b/src/addons/mod/choice/components/index/index.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import { Component, Optional, OnInit } from '@angular/core';
+import { CoreError } from '@classes/errors/error';
 import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
 import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
 import { IonContent } from '@ionic/angular';
@@ -454,22 +455,14 @@ export class AddonModChoiceIndexComponent extends CoreCourseModuleMainActivityCo
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected sync(): Promise<AddonModChoiceSyncResult> {
-        return AddonModChoiceSync.syncChoice(this.choice!.id, this.userId);
-    }
+        if (!this.choice) {
+            throw new CoreError('Cannot sync without a choice.');
+        }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns Whether it succeed or not.
-     */
-    protected hasSyncSucceed(result: AddonModChoiceSyncResult): boolean {
-        return result.updated;
+        return AddonModChoiceSync.syncChoice(this.choice.id, this.userId);
     }
 
 }
diff --git a/src/addons/mod/choice/services/choice-sync.ts b/src/addons/mod/choice/services/choice-sync.ts
index d0b74a684..c98d270a5 100644
--- a/src/addons/mod/choice/services/choice-sync.ts
+++ b/src/addons/mod/choice/services/choice-sync.ts
@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCourseActivitySyncBaseProvider } from '@features/course/classes/activity-sync';
+import { CoreSyncResult } from '@services/sync';
 import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
@@ -217,10 +218,7 @@ export const AddonModChoiceSync = makeSingleton(AddonModChoiceSyncProvider);
 /**
  * Data returned by a choice sync.
  */
-export type AddonModChoiceSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
+export type AddonModChoiceSyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNCED event.
diff --git a/src/addons/mod/data/components/index/index.ts b/src/addons/mod/data/components/index/index.ts
index 36948b327..2cdac62c5 100644
--- a/src/addons/mod/data/components/index/index.ts
+++ b/src/addons/mod/data/components/index/index.ts
@@ -519,24 +519,12 @@ export class AddonModDataIndexComponent extends CoreCourseModuleMainActivityComp
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected sync(): Promise<AddonModDataSyncResult> {
         return AddonModDataPrefetchHandler.sync(this.module, this.courseId);
     }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
-     */
-    protected hasSyncSucceed(result: AddonModDataSyncResult): boolean {
-        return result.updated;
-    }
-
     /**
      * @inheritdoc
      */
diff --git a/src/addons/mod/data/services/data-sync.ts b/src/addons/mod/data/services/data-sync.ts
index 5e76877bc..cd2e2ccea 100644
--- a/src/addons/mod/data/services/data-sync.ts
+++ b/src/addons/mod/data/services/data-sync.ts
@@ -24,7 +24,7 @@ import { CoreRatingSync } from '@features/rating/services/rating-sync';
 import { CoreNetwork } from '@services/network';
 import { CoreFileEntry } from '@services/file-helper';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreTextUtils } from '@services/utils/text';
 import { CoreUtils } from '@services/utils/utils';
 import { Translate, makeSingleton } from '@singletons';
@@ -477,10 +477,7 @@ export type AddonModDataSyncEntryResult = {
 /**
  * Data returned by a database sync.
  */
-export type AddonModDataSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
+export type AddonModDataSyncResult = CoreSyncResult;
 
 export type AddonModDataAutoSyncData = {
     dataId: number;
diff --git a/src/addons/mod/feedback/components/index/index.ts b/src/addons/mod/feedback/components/index/index.ts
index c02c0fa53..2f877c17a 100644
--- a/src/addons/mod/feedback/components/index/index.ts
+++ b/src/addons/mod/feedback/components/index/index.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import { Component, Input, Optional, ViewChild, OnInit, OnDestroy } from '@angular/core';
+import { CoreError } from '@classes/errors/error';
 import { CoreTabsComponent } from '@components/tabs/tabs';
 import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
 import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
@@ -477,14 +478,11 @@ export class AddonModFeedbackIndexComponent extends CoreCourseModuleMainActivity
      * @inheritdoc
      */
     protected sync(): Promise<AddonModFeedbackSyncResult> {
-        return AddonModFeedbackSync.syncFeedback(this.feedback!.id);
-    }
+        if (!this.feedback) {
+            throw new CoreError('Cannot sync without a feedback.');
+        }
 
-    /**
-     * @inheritdoc
-     */
-    protected hasSyncSucceed(result: AddonModFeedbackSyncResult): boolean {
-        return result.updated;
+        return AddonModFeedbackSync.syncFeedback(this.feedback.id);
     }
 
     /**
diff --git a/src/addons/mod/feedback/services/feedback-sync.ts b/src/addons/mod/feedback/services/feedback-sync.ts
index 5f84a7ceb..32f6791ef 100644
--- a/src/addons/mod/feedback/services/feedback-sync.ts
+++ b/src/addons/mod/feedback/services/feedback-sync.ts
@@ -20,7 +20,7 @@ import { CoreCourse, CoreCourseAnyModuleData } from '@features/course/services/c
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -292,10 +292,7 @@ export const AddonModFeedbackSync = makeSingleton(AddonModFeedbackSyncProvider);
 /**
  * Data returned by a feedback sync.
  */
-export type AddonModFeedbackSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
+export type AddonModFeedbackSyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNCED event.
diff --git a/src/addons/mod/forum/components/index/index.ts b/src/addons/mod/forum/components/index/index.ts
index 3dd733ad9..bb604e3f2 100644
--- a/src/addons/mod/forum/components/index/index.ts
+++ b/src/addons/mod/forum/components/index/index.ts
@@ -500,24 +500,12 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected sync(): Promise<AddonModForumSyncResult> {
         return AddonModForumPrefetchHandler.sync(this.module, this.courseId);
     }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns Whether it succeed or not.
-     */
-    protected hasSyncSucceed(result: AddonModForumSyncResult): boolean {
-        return result.updated;
-    }
-
     /**
      * Compares sync event data with current data to check if refresh content is needed.
      *
diff --git a/src/addons/mod/forum/services/forum-sync.ts b/src/addons/mod/forum/services/forum-sync.ts
index 37e88fc29..b2324c12d 100644
--- a/src/addons/mod/forum/services/forum-sync.ts
+++ b/src/addons/mod/forum/services/forum-sync.ts
@@ -21,7 +21,7 @@ import { CoreRatingSync } from '@features/rating/services/rating-sync';
 import { CoreNetwork } from '@services/network';
 import { CoreGroups } from '@services/groups';
 import { CoreSites } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -221,7 +221,7 @@ export class AddonModForumSyncProvider extends CoreCourseActivitySyncBaseProvide
         };
 
         // Sync offline logs.
-        const syncDiscussions = async (): Promise<{ warnings: string[]; updated: boolean }> => {
+        const syncDiscussions = async (): Promise<AddonModForumSyncResult> => {
             await CoreUtils.ignoreErrors(
                 CoreCourseLogHelper.syncActivity(AddonModForumProvider.COMPONENT, forumId, siteId),
             );
@@ -643,10 +643,7 @@ export const AddonModForumSync = makeSingleton(AddonModForumSyncProvider);
 /**
  * Result of forum sync.
  */
-export type AddonModForumSyncResult = {
-    updated: boolean;
-    warnings: string[];
-};
+export type AddonModForumSyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNCED event.
diff --git a/src/addons/mod/forum/services/handlers/prefetch.ts b/src/addons/mod/forum/services/handlers/prefetch.ts
index b03910690..29124b40e 100644
--- a/src/addons/mod/forum/services/handlers/prefetch.ts
+++ b/src/addons/mod/forum/services/handlers/prefetch.ts
@@ -22,7 +22,7 @@ import { CoreCourse, CoreCourseAnyModuleData, CoreCourseCommonModWSOptions } fro
 import { CoreUser } from '@features/user/services/user';
 import { CoreGroups, CoreGroupsProvider } from '@services/groups';
 import { CoreUtils } from '@services/utils/utils';
-import { AddonModForumSync } from '../forum-sync';
+import { AddonModForumSync, AddonModForumSyncResult } from '../forum-sync';
 import { makeSingleton } from '@singletons';
 import { CoreCourses } from '@features/courses/services/courses';
 
@@ -341,11 +341,3 @@ export class AddonModForumPrefetchHandlerService extends CoreCourseActivityPrefe
 }
 
 export const AddonModForumPrefetchHandler = makeSingleton(AddonModForumPrefetchHandlerService);
-
-/**
- * Data returned by a forum sync.
- */
-export type AddonModForumSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
diff --git a/src/addons/mod/glossary/components/index/index.ts b/src/addons/mod/glossary/components/index/index.ts
index 5b22a4cd4..6b0acca1c 100644
--- a/src/addons/mod/glossary/components/index/index.ts
+++ b/src/addons/mod/glossary/components/index/index.ts
@@ -215,24 +215,12 @@ export class AddonModGlossaryIndexComponent extends CoreCourseModuleMainActivity
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected sync(): Promise<AddonModGlossarySyncResult> {
         return AddonModGlossaryPrefetchHandler.sync(this.module, this.courseId);
     }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns Whether it succeed or not.
-     */
-    protected hasSyncSucceed(result: AddonModGlossarySyncResult): boolean {
-        return result.updated;
-    }
-
     /**
      * Compares sync event data with current data to check if refresh content is needed.
      *
diff --git a/src/addons/mod/glossary/services/glossary-sync.ts b/src/addons/mod/glossary/services/glossary-sync.ts
index 8db74bcc1..0fc65ad13 100644
--- a/src/addons/mod/glossary/services/glossary-sync.ts
+++ b/src/addons/mod/glossary/services/glossary-sync.ts
@@ -21,7 +21,7 @@ import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreRatingSync } from '@features/rating/services/rating-sync';
 import { CoreNetwork } from '@services/network';
 import { CoreSites } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -344,10 +344,7 @@ export const AddonModGlossarySync = makeSingleton(AddonModGlossarySyncProvider);
 /**
  * Data returned by a glossary sync.
  */
-export type AddonModGlossarySyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
+export type AddonModGlossarySyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNCED event.
diff --git a/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts b/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
index 5eb33e384..7d9c3fb19 100644
--- a/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
+++ b/src/addons/mod/h5pactivity/services/h5pactivity-sync.ts
@@ -16,6 +16,7 @@ import { Injectable } from '@angular/core';
 
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCourseActivitySyncBaseProvider } from '@features/course/classes/activity-sync';
+import { CoreSyncResult } from '@services/sync';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreXAPIOffline } from '@features/xapi/services/offline';
 import { CoreXAPI } from '@features/xapi/services/xapi';
@@ -197,10 +198,7 @@ export const AddonModH5PActivitySync = makeSingleton(AddonModH5PActivitySyncProv
 /**
  * Sync result.
  */
-export type AddonModH5PActivitySyncResult = {
-    updated: boolean;
-    warnings: string[];
-};
+export type AddonModH5PActivitySyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNC event.
diff --git a/src/addons/mod/lesson/components/index/index.ts b/src/addons/mod/lesson/components/index/index.ts
index 5495057e2..bd66d2b49 100644
--- a/src/addons/mod/lesson/components/index/index.ts
+++ b/src/addons/mod/lesson/components/index/index.ts
@@ -47,6 +47,7 @@ import {
 } from '../../services/lesson-sync';
 import { AddonModLessonModuleHandlerService } from '../../services/handlers/module';
 import { CoreTime } from '@singletons/time';
+import { CoreError } from '@classes/errors/error';
 
 /**
  * Component that displays a lesson entry page.
@@ -270,10 +271,7 @@ export class AddonModLessonIndexComponent extends CoreCourseModuleMainActivityCo
     }
 
     /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
+     * @inheritdoc
      */
     protected hasSyncSucceed(result: AddonModLessonSyncResult): boolean {
         if (result.updated || this.dataSent) {
@@ -637,12 +635,14 @@ export class AddonModLessonIndexComponent extends CoreCourseModuleMainActivityCo
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected async sync(): Promise<AddonModLessonSyncResult> {
-        const result = await AddonModLessonSync.syncLesson(this.lesson!.id, true);
+        if (!this.lesson) {
+            throw new CoreError('Cannot sync without a lesson.');
+        }
+
+        const result = await AddonModLessonSync.syncLesson(this.lesson.id, true);
 
         if (!result.updated && this.dataSent && this.isPrefetched()) {
             // The user sent data to server, but not in the sync process. Check if we need to fetch data.
diff --git a/src/addons/mod/lesson/services/lesson-sync.ts b/src/addons/mod/lesson/services/lesson-sync.ts
index 1a4241178..adf4eb126 100644
--- a/src/addons/mod/lesson/services/lesson-sync.ts
+++ b/src/addons/mod/lesson/services/lesson-sync.ts
@@ -21,7 +21,7 @@ import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreTimeUtils } from '@services/utils/time';
 import { CoreUrlUtils } from '@services/utils/url';
 import { CoreUtils } from '@services/utils/utils';
@@ -495,9 +495,7 @@ export const AddonModLessonSync = makeSingleton(AddonModLessonSyncProvider);
 /**
  * Data returned by a lesson sync.
  */
-export type AddonModLessonSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
+export type AddonModLessonSyncResult = CoreSyncResult & {
     courseId?: number; // Course the lesson belongs to (if known).
 };
 
diff --git a/src/addons/mod/quiz/components/index/index.ts b/src/addons/mod/quiz/components/index/index.ts
index c4adff103..98b84d041 100644
--- a/src/addons/mod/quiz/components/index/index.ts
+++ b/src/addons/mod/quiz/components/index/index.ts
@@ -418,10 +418,7 @@ export class AddonModQuizIndexComponent extends CoreCourseModuleMainActivityComp
     }
 
     /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
+     * @inheritdoc
      */
     protected hasSyncSucceed(result: AddonModQuizSyncResult): boolean {
         if (result.attemptFinished) {
@@ -553,9 +550,7 @@ export class AddonModQuizIndexComponent extends CoreCourseModuleMainActivityComp
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected async sync(): Promise<AddonModQuizSyncResult> {
         if (!this.candidateQuiz) {
diff --git a/src/addons/mod/quiz/services/quiz-offline.ts b/src/addons/mod/quiz/services/quiz-offline.ts
index 5009a68d7..ed477be09 100644
--- a/src/addons/mod/quiz/services/quiz-offline.ts
+++ b/src/addons/mod/quiz/services/quiz-offline.ts
@@ -13,7 +13,6 @@
 // limitations under the License.
 
 import { Injectable } from '@angular/core';
-import { CoreError } from '@classes/errors/error';
 
 import { CoreQuestionBehaviourDelegate, CoreQuestionQuestionWithAnswers } from '@features/question/services/behaviour-delegate';
 import { CoreQuestionAnswerDBRecord } from '@features/question/services/database/question';
diff --git a/src/addons/mod/quiz/services/quiz-sync.ts b/src/addons/mod/quiz/services/quiz-sync.ts
index 4b6a573ae..74871a22e 100644
--- a/src/addons/mod/quiz/services/quiz-sync.ts
+++ b/src/addons/mod/quiz/services/quiz-sync.ts
@@ -23,7 +23,7 @@ import { CoreQuestion, CoreQuestionQuestionParsed } from '@features/question/ser
 import { CoreQuestionDelegate } from '@features/question/services/question-delegate';
 import { CoreNetwork } from '@services/network';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -482,10 +482,8 @@ export const AddonModQuizSync = makeSingleton(AddonModQuizSyncProvider);
 /**
  * Data returned by a quiz sync.
  */
-export type AddonModQuizSyncResult = {
-    warnings: string[]; // List of warnings.
+export type AddonModQuizSyncResult = CoreSyncResult & {
     attemptFinished: boolean; // Whether an attempt was finished in the site due to the sync.
-    updated: boolean;
 };
 
 /**
diff --git a/src/addons/mod/scorm/components/index/index.ts b/src/addons/mod/scorm/components/index/index.ts
index f3c0a7307..90e36e1ed 100644
--- a/src/addons/mod/scorm/components/index/index.ts
+++ b/src/addons/mod/scorm/components/index/index.ts
@@ -14,6 +14,7 @@
 
 import { CoreConstants } from '@/core/constants';
 import { Component, Input, OnInit, Optional } from '@angular/core';
+import { CoreError } from '@classes/errors/error';
 import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
 import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
 import { CoreCourse } from '@features/course/services/course';
@@ -364,10 +365,7 @@ export class AddonModScormIndexComponent extends CoreCourseModuleMainActivityCom
     }
 
     /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
+     * @inheritdoc
      */
     protected hasSyncSucceed(result: AddonModScormSyncResult): boolean {
         if (result.updated || this.dataSent) {
@@ -377,7 +375,7 @@ export class AddonModScormIndexComponent extends CoreCourseModuleMainActivityCom
 
         this.dataSent = false;
 
-        return true;
+        return result.updated;
     }
 
     /**
@@ -608,9 +606,9 @@ export class AddonModScormIndexComponent extends CoreCourseModuleMainActivityCom
      * @param retries Number of retries done.
      * @returns Promise resolved when done.
      */
-    protected async sync(retries = 0): Promise<AddonModScormSyncResult | undefined> {
+    protected async sync(retries = 0): Promise<AddonModScormSyncResult> {
         if (!this.scorm) {
-            return;
+            throw new CoreError('Cannot sync without a scorm.');
         }
 
         if (CoreSync.isBlocked(AddonModScormProvider.COMPONENT, this.scorm.id) && retries < 5) {
diff --git a/src/addons/mod/scorm/services/scorm-sync.ts b/src/addons/mod/scorm/services/scorm-sync.ts
index cfae16dbb..b55470e84 100644
--- a/src/addons/mod/scorm/services/scorm-sync.ts
+++ b/src/addons/mod/scorm/services/scorm-sync.ts
@@ -18,7 +18,7 @@ import { CoreCourseActivitySyncBaseProvider } from '@features/course/classes/act
 import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreSites, CoreSitesReadingStrategy } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -841,18 +841,14 @@ export const AddonModScormSync = makeSingleton(AddonModScormSyncProvider);
 /**
  * Data returned by a SCORM sync.
  */
-export type AddonModScormSyncResult = {
-    warnings: string[]; // List of warnings.
+export type AddonModScormSyncResult = CoreSyncResult & {
     attemptFinished: boolean; // Whether an attempt was finished in the site due to the sync,
-    updated: boolean; // Whether some data was sent to the site.
 };
 
 /**
  * Auto sync event data.
  */
-export type AddonModScormAutoSyncEventData = {
+export type AddonModScormAutoSyncEventData = CoreSyncResult & {
     scormId: number;
     attemptFinished: boolean;
-    warnings: string[];
-    updated: boolean;
 };
diff --git a/src/addons/mod/survey/components/index/index.ts b/src/addons/mod/survey/components/index/index.ts
index 788ed1a0d..8fa968dda 100644
--- a/src/addons/mod/survey/components/index/index.ts
+++ b/src/addons/mod/survey/components/index/index.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import { Component, OnInit, Optional } from '@angular/core';
+import { CoreError } from '@classes/errors/error';
 import { CoreIonLoadingElement } from '@classes/ion-loading';
 import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
 import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
@@ -117,8 +118,8 @@ export class AddonModSurveyIndexComponent extends CoreCourseModuleMainActivityCo
 
         if (sync) {
             // Try to synchronize the survey.
-            const answersSent = await this.syncActivity(showErrors);
-            if (answersSent) {
+            const updated = await this.syncActivity(showErrors);
+            if (updated) {
                 // Answers were sent, update the survey.
                 this.survey = await AddonModSurvey.getSurvey(this.courseId, this.module.id);
             }
@@ -236,26 +237,14 @@ export class AddonModSurveyIndexComponent extends CoreCourseModuleMainActivityCo
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
-    protected async sync(): Promise<AddonModSurveySyncResult | void> {
+    protected async sync(): Promise<AddonModSurveySyncResult> {
         if (!this.survey) {
-            return;
+            throw new CoreError('Cannot sync without a survey.');
         }
 
         return AddonModSurveySync.syncSurvey(this.survey.id, this.currentUserId);
     }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
-     */
-    protected hasSyncSucceed(result: AddonModSurveySyncResult): boolean {
-        return result.answersSent;
-    }
-
 }
diff --git a/src/addons/mod/survey/services/survey-sync.ts b/src/addons/mod/survey/services/survey-sync.ts
index 455039f7b..6089e342a 100644
--- a/src/addons/mod/survey/services/survey-sync.ts
+++ b/src/addons/mod/survey/services/survey-sync.ts
@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCourseActivitySyncBaseProvider } from '@features/course/classes/activity-sync';
+import { CoreSyncResult } from '@services/sync';
 import { CoreCourse } from '@features/course/services/course';
 import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
@@ -80,7 +81,7 @@ export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvid
                 ? this.syncSurvey(entry.surveyid, entry.userid, siteId)
                 : this.syncSurveyIfNeeded(entry.surveyid, entry.userid, siteId));
 
-            if (result && result.answersSent) {
+            if (result && result.updated) {
                 // Sync successful, send event.
                 CoreEvents.trigger(AddonModSurveySyncProvider.AUTO_SYNCED, {
                     surveyId: entry.surveyid,
@@ -150,7 +151,7 @@ export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvid
     protected async performSyncSurvey(surveyId: number, userId: number, siteId: string): Promise<AddonModSurveySyncResult> {
         const result: AddonModSurveySyncResult = {
             warnings: [],
-            answersSent: false,
+            updated: false,
         };
 
         // Sync offline logs.
@@ -179,7 +180,7 @@ export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvid
             try {
                 await AddonModSurvey.submitAnswersOnline(surveyId, data.answers, siteId);
 
-                result.answersSent = true;
+                result.updated = true;
 
                 // Answers sent, delete them.
                 await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId, userId);
@@ -190,7 +191,7 @@ export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvid
                 }
 
                 // The WebService has thrown an error, this means that answers cannot be submitted. Delete them.
-                result.answersSent = true;
+                result.updated = true;
 
                 await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId, userId);
 
@@ -236,9 +237,7 @@ declare module '@singletons/events' {
 /**
  * Data returned by a assign sync.
  */
-export type AddonModSurveySyncResult = {
-    warnings: string[]; // List of warnings.
-    answersSent: boolean; // Whether some data was sent to the server or offline data was updated.
+export type AddonModSurveySyncResult = CoreSyncResult & {
     courseId?: number; // Course the survey belongs to (if known).
 };
 
diff --git a/src/addons/mod/wiki/components/index/index.ts b/src/addons/mod/wiki/components/index/index.ts
index 333b921d6..3b724896a 100644
--- a/src/addons/mod/wiki/components/index/index.ts
+++ b/src/addons/mod/wiki/components/index/index.ts
@@ -707,12 +707,9 @@ export class AddonModWikiIndexComponent extends CoreCourseModuleMainActivityComp
     }
 
     /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
+     * @inheritdoc
      */
-    protected hasSyncSucceed(result: AddonModWikiSyncWikiResult | undefined): boolean {
+    protected hasSyncSucceed(result: AddonModWikiSyncWikiResult): boolean {
         if (!result) {
             return false;
         }
@@ -843,13 +840,11 @@ export class AddonModWikiIndexComponent extends CoreCourseModuleMainActivityComp
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
-    protected async sync(): Promise<AddonModWikiSyncWikiResult | undefined> {
+    protected async sync(): Promise<AddonModWikiSyncWikiResult> {
         if (!this.wiki) {
-            return;
+            throw new CoreError('Cannot sync without a wiki.');
         }
 
         return AddonModWikiSync.syncWiki(this.wiki.id, this.courseId, this.wiki.coursemodule);
diff --git a/src/addons/mod/wiki/services/wiki-sync.ts b/src/addons/mod/wiki/services/wiki-sync.ts
index 906c62365..0ba10b7f2 100644
--- a/src/addons/mod/wiki/services/wiki-sync.ts
+++ b/src/addons/mod/wiki/services/wiki-sync.ts
@@ -19,7 +19,7 @@ import { CoreCourseLogHelper } from '@features/course/services/log-helper';
 import { CoreNetwork } from '@services/network';
 import { CoreGroups } from '@services/groups';
 import { CoreSites } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreUtils } from '@services/utils/utils';
 import { makeSingleton, Translate } from '@singletons';
 import { CoreEvents } from '@singletons/events';
@@ -345,9 +345,7 @@ export const AddonModWikiSync = makeSingleton(AddonModWikiSyncProvider);
 /**
  * Data returned by a subwiki sync.
  */
-export type AddonModWikiSyncSubwikiResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether data was updated in the site.
+export type AddonModWikiSyncSubwikiResult = CoreSyncResult & {
     created: AddonModWikiCreatedPage[]; // List of created pages.
     discarded: AddonModWikiDiscardedPage[]; // List of discarded pages.
 };
@@ -355,9 +353,7 @@ export type AddonModWikiSyncSubwikiResult = {
 /**
  * Data returned by a wiki sync.
  */
-export type AddonModWikiSyncWikiResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether data was updated in the site.
+export type AddonModWikiSyncWikiResult = CoreSyncResult & {
     subwikis: {
         [subwikiId: number]: { // List of subwikis.
             created: AddonModWikiCreatedPage[];
diff --git a/src/addons/mod/workshop/components/index/index.ts b/src/addons/mod/workshop/components/index/index.ts
index 70933bd6f..cfed3a329 100644
--- a/src/addons/mod/workshop/components/index/index.ts
+++ b/src/addons/mod/workshop/components/index/index.ts
@@ -528,9 +528,7 @@ export class AddonModWorkshopIndexComponent extends CoreCourseModuleMainActivity
     }
 
     /**
-     * Performs the sync of the activity.
-     *
-     * @returns Promise resolved when done.
+     * @inheritdoc
      */
     protected sync(): Promise<AddonModWorkshopSyncResult> {
         if (!this.workshop) {
@@ -540,16 +538,6 @@ export class AddonModWorkshopIndexComponent extends CoreCourseModuleMainActivity
         return AddonModWorkshopSync.syncWorkshop(this.workshop.id);
     }
 
-    /**
-     * Checks if sync has succeed from result sync data.
-     *
-     * @param result Data returned on the sync function.
-     * @returns If suceed or not.
-     */
-    protected hasSyncSucceed(result: AddonModWorkshopSyncResult): boolean {
-        return result.updated;
-    }
-
     /**
      * @inheritdoc
      */
diff --git a/src/addons/mod/workshop/services/workshop-sync.ts b/src/addons/mod/workshop/services/workshop-sync.ts
index 695afa417..3e345020b 100644
--- a/src/addons/mod/workshop/services/workshop-sync.ts
+++ b/src/addons/mod/workshop/services/workshop-sync.ts
@@ -20,7 +20,7 @@ import { CoreFileUploaderStoreFilesResult } from '@features/fileuploader/service
 import { CoreNetwork } from '@services/network';
 import { CoreFileEntry } from '@services/file-helper';
 import { CoreSites } from '@services/sites';
-import { CoreSync } from '@services/sync';
+import { CoreSync, CoreSyncResult } from '@services/sync';
 import { CoreTextUtils } from '@services/utils/text';
 import { CoreUtils } from '@services/utils/utils';
 import { Translate, makeSingleton } from '@singletons';
@@ -639,7 +639,4 @@ export type AddonModWorkshopAutoSyncData = {
     warnings: string[];
 };
 
-export type AddonModWorkshopSyncResult = {
-    warnings: string[];
-    updated: boolean;
-};
+export type AddonModWorkshopSyncResult = CoreSyncResult;
diff --git a/src/core/features/comments/services/comments-sync.ts b/src/core/features/comments/services/comments-sync.ts
index 78a9d046a..1d37106cd 100644
--- a/src/core/features/comments/services/comments-sync.ts
+++ b/src/core/features/comments/services/comments-sync.ts
@@ -23,6 +23,7 @@ import { CoreNetwork } from '@services/network';
 import { CoreUtils } from '@services/utils/utils';
 import { CoreNetworkError } from '@classes/errors/network-error';
 import { CoreCommentsDBRecord, CoreCommentsDeletedDBRecord } from './database/comments';
+import { CoreSyncResult } from '@services/sync';
 
 /**
  * Service to sync omments.
@@ -318,10 +319,7 @@ export class CoreCommentsSyncProvider extends CoreSyncBaseProvider<CoreCommentsS
 }
 export const CoreCommentsSync = makeSingleton(CoreCommentsSyncProvider);
 
-export type CoreCommentsSyncResult = {
-    warnings: string[]; // List of warnings.
-    updated: boolean; // Whether some data was sent to the server or offline data was updated.
-};
+export type CoreCommentsSyncResult = CoreSyncResult;
 
 /**
  * Data passed to AUTO_SYNCED event.
diff --git a/src/core/features/course/classes/main-activity-component.ts b/src/core/features/course/classes/main-activity-component.ts
index 66b9ed4e7..4e8a8764e 100644
--- a/src/core/features/course/classes/main-activity-component.ts
+++ b/src/core/features/course/classes/main-activity-component.ts
@@ -20,9 +20,9 @@ import { CoreEventObserver, CoreEvents } from '@singletons/events';
 import { CoreCourse } from '../services/course';
 import { CoreUtils } from '@services/utils/utils';
 import { CoreDomUtils } from '@services/utils/dom';
-import { CoreWSExternalWarning } from '@services/ws';
 import { CoreCourseContentsPage } from '../pages/contents/contents';
 import { CoreSites } from '@services/sites';
+import { CoreSyncResult } from '@services/sync';
 
 /**
  * Template class to easily create CoreCourseModuleMainComponent of activities.
@@ -188,32 +188,34 @@ export class CoreCourseModuleMainActivityComponent extends CoreCourseModuleMainR
      *
      * @returns Promise resolved when done.
      */
-    protected async sync(): Promise<unknown> {
-        return {};
+    protected async sync(): Promise<CoreSyncResult> {
+        return {
+            updated: false,
+            warnings: [],
+        };
     }
 
     /**
-     * Checks if sync has succeed from result sync data.
+     * Checks if sync has updated data on the server.
      *
      * @param result Data returned on the sync function.
-     * @returns If suceed or not.
+     * @returns If data has been updated or not.
      */
-    // eslint-disable-next-line @typescript-eslint/no-unused-vars
-    protected hasSyncSucceed(result: unknown): boolean {
-        return true;
+    protected hasSyncSucceed(result: CoreSyncResult): boolean {
+        return result.updated;
     }
 
     /**
      * Tries to synchronize the activity.
      *
      * @param showErrors If show errors to the user of hide them.
-     * @returns Promise resolved with true if sync succeed, or false if failed.
+     * @returns Promise resolved with true if sync hast updated data to the server, false otherwise.
      */
     protected async syncActivity(showErrors: boolean = false): Promise<boolean> {
         try {
-            const result = <{warnings?: CoreWSExternalWarning[]}> await this.sync();
+            const result = await this.sync();
 
-            if (result?.warnings?.length) {
+            if (result.warnings.length) {
                 CoreDomUtils.showErrorModal(result.warnings[0]);
             }
 
diff --git a/src/core/services/sync.ts b/src/core/services/sync.ts
index 70f990d4f..36ef93ac5 100644
--- a/src/core/services/sync.ts
+++ b/src/core/services/sync.ts
@@ -183,3 +183,8 @@ export class CoreSyncProvider {
 }
 
 export const CoreSync = makeSingleton(CoreSyncProvider);
+
+export type CoreSyncResult = {
+    warnings: string[]; // List of warnings.
+    updated: boolean; // Whether some data was sent to the server or offline data was updated.
+};