diff --git a/src/addons/mod/forum/components/index/index.ts b/src/addons/mod/forum/components/index/index.ts
index 4562d9917..802085a89 100644
--- a/src/addons/mod/forum/components/index/index.ts
+++ b/src/addons/mod/forum/components/index/index.ts
@@ -380,7 +380,9 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
         }
 
         // Fill user data for Offline discussions (should be already cached).
-        const promises = offlineDiscussions.map(async (discussion: any) => {
+        const promises = offlineDiscussions.map(async (offlineDiscussion) => {
+            const discussion = offlineDiscussion as unknown as AddonModForumDiscussion;
+
             if (discussion.parent === 0 || forum.type === 'single') {
                 // Do not show author for first post and type single.
                 return;
diff --git a/src/addons/mod/forum/components/post/post.ts b/src/addons/mod/forum/components/post/post.ts
index 7a0405051..7d174bb9b 100644
--- a/src/addons/mod/forum/components/post/post.ts
+++ b/src/addons/mod/forum/components/post/post.ts
@@ -71,8 +71,8 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
     @Input() discussion?: AddonModForumDiscussion; // Post's' discussion, only for starting posts.
     @Input() component!: string; // Component this post belong to.
     @Input() componentId!: number; // Component ID.
-    @Input() replyData: any; // Object with the new post data. Usually shared between posts.
-    @Input() originalData: any; // Object with the original post data. Usually shared between posts.
+    @Input() replyData!: AddonModForumReply; // Object with the new post data. Usually shared between posts.
+    @Input() originalData!: Omit<AddonModForumReply, 'id'>; // Object with the original post data. Usually shared between posts.
     @Input() trackPosts!: boolean; // True if post is being tracked.
     @Input() forum!: AddonModForumData; // The forum the post belongs to. Required for attachments and offline posts.
     @Input() accessInfo!: AddonModForumAccessInformation; // Forum access information.
@@ -103,7 +103,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
     get showForm(): boolean {
         return this.post.id > 0
             ? !this.replyData.isEditing && this.replyData.replyingTo === this.post.id
-            : this.replyData.isEditing && this.replyData.replyingTo === this.post.parentid;
+            : !!this.replyData.isEditing && this.replyData.replyingTo === this.post.parentid;
     }
 
     /**
@@ -275,7 +275,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
         }
 
         // Add some HTML to the message if needed.
-        const message = CoreTextUtils.formatHtmlLines(data.message);
+        const message = CoreTextUtils.formatHtmlLines(data.message!);
         const files = data.files;
         const options: AddonModForumUpdateDiscussionPostWSOptionsObject = {};
 
@@ -295,14 +295,14 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
             }
 
             // Try to send it to server.
-            const sent = await AddonModForum.updatePost(this.post.id, data.subject, message, options);
+            const sent = await AddonModForum.updatePost(this.post.id, data.subject!, message, options);
 
             if (sent && this.forum.id) {
                 // Data sent to server, delete stored files (if any).
                 AddonModForumHelper.deleteReplyStoredFiles(this.forum.id, this.post.id);
 
                 this.onPostChange.emit();
-                this.post.subject = data.subject;
+                this.post.subject = data.subject!;
                 this.post.message = message;
                 this.post.attachments = data.files;
             }
@@ -419,7 +419,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy, OnChanges
         let saveOffline = false;
         let message = this.replyData.message;
         const subject = this.replyData.subject;
-        const replyingTo = this.replyData.replyingTo;
+        const replyingTo = this.replyData.replyingTo!;
         const files = this.replyData.files || [];
         const options: AddonModForumReplyOptions = {};
         const modal = await CoreDomUtils.showModalLoading('core.sending', true);
diff --git a/src/addons/mod/forum/pages/discussion/discussion.page.ts b/src/addons/mod/forum/pages/discussion/discussion.page.ts
index edf8d9fdd..b059151df 100644
--- a/src/addons/mod/forum/pages/discussion/discussion.page.ts
+++ b/src/addons/mod/forum/pages/discussion/discussion.page.ts
@@ -38,6 +38,7 @@ import {
     AddonModForumDiscussion,
     AddonModForumPost,
     AddonModForumProvider,
+    AddonModForumReply,
 } from '../../services/forum';
 import { AddonModForumHelper } from '../../services/forum-helper';
 import { AddonModForumOffline } from '../../services/forum-offline';
@@ -72,18 +73,18 @@ export class AddonModForumDiscussionPage implements OnInit, AfterViewInit, OnDes
     postHasOffline!: boolean;
     sort: SortType = 'nested';
     trackPosts!: boolean;
-    replyData = {
+    replyData: Omit<AddonModForumReply, 'id'> = {
         replyingTo: 0,
         isEditing: false,
         subject: '',
-        message: null, // Null means empty or just white space.
+        message: null,
         files: [],
         isprivatereply: false,
     };
 
-    originalData = {
-        subject: null, // Null means original data is not set.
-        message: null, // Null means empty or just white space.
+    originalData: Omit<AddonModForumReply, 'id'> = {
+        subject: null,
+        message: null,
         files: [],
         isprivatereply: false,
     };
diff --git a/src/addons/mod/forum/services/forum-helper.ts b/src/addons/mod/forum/services/forum-helper.ts
index 140853e36..0519efe28 100644
--- a/src/addons/mod/forum/services/forum-helper.ts
+++ b/src/addons/mod/forum/services/forum-helper.ts
@@ -368,25 +368,25 @@ export class AddonModForumHelperProvider {
     /**
      * Check if the data of a post/discussion has changed.
      *
-     * @param post Current data.
+     * @param reply Current data.
      * @param original Original ata.
      * @return True if data has changed, false otherwise.
      */
-    hasPostDataChanged(post: any, original?: any): boolean {
+    hasPostDataChanged(reply: AddonModForumPostData, original?: AddonModForumPostData): boolean {
         if (!original || original.subject == null) {
             // There is no original data, assume it hasn't changed.
             return false;
         }
 
-        if (post.subject != original.subject || post.message != original.message) {
+        if (reply.subject != original.subject || reply.message != original.message) {
             return true;
         }
 
-        if (post.isprivatereply != original.isprivatereply) {
+        if (reply.isprivatereply != original.isprivatereply) {
             return true;
         }
 
-        return CoreFileUploader.areFileListDifferent(post.files, original.files);
+        return CoreFileUploader.areFileListDifferent(reply.files ?? [], original.files ?? []);
     }
 
     /**
@@ -541,3 +541,13 @@ export class AddonModForumHelperProvider {
 }
 
 export const AddonModForumHelper = makeSingleton(AddonModForumHelperProvider);
+
+/**
+ * Forum post data used to check changes.
+ */
+type AddonModForumPostData = {
+    subject?: string | null;
+    message?: string | null;
+    isprivatereply?: boolean;
+    files?: CoreFileEntry[];
+};
diff --git a/src/addons/mod/forum/services/forum.ts b/src/addons/mod/forum/services/forum.ts
index 582c13e65..c12f4be48 100644
--- a/src/addons/mod/forum/services/forum.ts
+++ b/src/addons/mod/forum/services/forum.ts
@@ -1407,7 +1407,7 @@ export type AddonModForumDiscussion = {
     mailnow: number; // Mail now?.
     userfullname: string | boolean; // Post author full name.
     usermodifiedfullname: string; // Post modifier full name.
-    userpictureurl: string; // Post author picture.
+    userpictureurl?: string; // Post author picture.
     usermodifiedpictureurl: string; // Post modifier picture.
     numreplies: number; // The number of replies in the discussion.
     numunread: number; // The number of unread discussions.
@@ -1564,9 +1564,12 @@ export type AddonModForumAccessInformation = {
  */
 export type AddonModForumReply = {
     id: number;
-    subject: string;
-    message: string;
+    subject: string | null; // Null means original data is not set.
+    message: string | null; // Null means empty or just white space.
     files: CoreFileEntry[];
+    replyingTo?: number;
+    isEditing?: boolean;
+    isprivatereply?: boolean;
 };
 
 /**
diff --git a/src/addons/mod/forum/services/handlers/discussion-link.ts b/src/addons/mod/forum/services/handlers/discussion-link.ts
index 245d7c558..8e821ed80 100644
--- a/src/addons/mod/forum/services/handlers/discussion-link.ts
+++ b/src/addons/mod/forum/services/handlers/discussion-link.ts
@@ -45,7 +45,7 @@ export class AddonModForumDiscussionLinkHandlerService extends CoreContentLinksH
         url: string,
         params: Params,
         courseId?: number,
-        data?: any,
+        data?: { instance?: string; cmid?: string; postid?: string },
     ): CoreContentLinksAction[] | Promise<CoreContentLinksAction[]> {
         data = data || {};
 
@@ -56,13 +56,13 @@ export class AddonModForumDiscussionLinkHandlerService extends CoreContentLinksH
             action: (siteId): void => {
                 const discussionId = parseInt(params.d, 10);
                 const pageParams: Params = {
-                    forumId: data.instance && parseInt(data.instance, 10),
-                    cmId: data.cmid && parseInt(data.cmid, 10),
+                    forumId: data?.instance && parseInt(data.instance, 10),
+                    cmId: data?.cmid && parseInt(data.cmid, 10),
                     courseId: courseId || parseInt(params.courseid, 10) || parseInt(params.cid, 10),
                 };
 
-                if (data.postid || params.urlHash) {
-                    pageParams.postId = parseInt(data.postid || params.urlHash.replace('p', ''));
+                if (data?.postid || params.urlHash) {
+                    pageParams.postId = parseInt(data?.postid || params.urlHash.replace('p', ''));
                 }
 
                 if (params.parent) {
diff --git a/src/addons/mod/resource/services/handlers/prefetch.ts b/src/addons/mod/resource/services/handlers/prefetch.ts
index 15886949e..f93df9fac 100644
--- a/src/addons/mod/resource/services/handlers/prefetch.ts
+++ b/src/addons/mod/resource/services/handlers/prefetch.ts
@@ -64,7 +64,7 @@ export class AddonModResourcePrefetchHandlerService extends CoreCourseResourcePr
             dirPath = await CoreFilepool.getPackageDirPathByUrl(CoreSites.getCurrentSiteId(), module.url!);
         }
 
-        const promises: Promise<any>[] = [];
+        const promises: Promise<unknown>[] = [];
 
         promises.push(super.downloadOrPrefetch(module, courseId, prefetch, dirPath));
 
diff --git a/src/core/classes/site.ts b/src/core/classes/site.ts
index 549ac2dcf..7fe336b26 100644
--- a/src/core/classes/site.ts
+++ b/src/core/classes/site.ts
@@ -560,7 +560,7 @@ export class CoreSite {
             return CoreUtils.clone(response);
         }
 
-        const promise = this.getFromCache<T>(method, data, preSets, false).catch(() => {
+        const promise = this.getFromCache<T>(method, data, preSets, false).catch(async () => {
             if (preSets.forceOffline) {
                 // Don't call the WS, just fail.
                 throw new CoreError(
@@ -569,13 +569,15 @@ export class CoreSite {
             }
 
             // Call the WS.
-            return this.callOrEnqueueRequest<T>(method, data, preSets, wsPreSets).then((response) => {
+            try {
+                const response = await this.callOrEnqueueRequest<T>(method, data, preSets, wsPreSets);
+
                 if (preSets.saveToCache) {
                     this.saveToCache(method, data, response, preSets);
                 }
 
                 return response;
-            }).catch((error) => {
+            } catch (error) {
                 if (error.errorcode == 'invalidtoken' ||
                     (error.errorcode == 'accessexception' && error.message.indexOf('Invalid token - token expired') > -1)) {
                     if (initialToken !== this.token && !retrying) {
@@ -585,7 +587,9 @@ export class CoreSite {
                         return this.request<T>(method, data, preSets, true);
                     } else if (CoreApp.isSSOAuthenticationOngoing()) {
                         // There's an SSO authentication ongoing, wait for it to finish and try again.
-                        return CoreApp.waitForSSOAuthentication().then(() => this.request<T>(method, data, preSets, true));
+                        await CoreApp.waitForSSOAuthentication();
+
+                        return this.request<T>(method, data, preSets, true);
                     }
 
                     // Session expired, trigger event.
@@ -649,9 +653,7 @@ export class CoreSite {
 
                 if (preSets.deleteCacheIfWSError && CoreUtils.isWebServiceError(error)) {
                     // Delete the cache entry and return the entry. Don't block the user with the delete.
-                    this.deleteFromCache(method, data, preSets).catch(() => {
-                        // Ignore errors.
-                    });
+                    CoreUtils.ignoreErrors(this.deleteFromCache(method, data, preSets));
 
                     throw new CoreWSError(error);
                 }
@@ -660,10 +662,12 @@ export class CoreSite {
                 preSets.omitExpires = true;
                 preSets.getFromCache = true;
 
-                return this.getFromCache<T>(method, data, preSets, true).catch(() => {
+                try {
+                    return await this.getFromCache<T>(method, data, preSets, true);
+                } catch (e) {
                     throw new CoreWSError(error);
-                });
-            });
+                }
+            }
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         }).then((response: any) => {
             // Check if the response is an error, this happens if the error was stored in the cache.
diff --git a/src/core/features/block/components/block/block.ts b/src/core/features/block/components/block/block.ts
index 05ee91cc0..2fe6f2a44 100644
--- a/src/core/features/block/components/block/block.ts
+++ b/src/core/features/block/components/block/block.ts
@@ -34,10 +34,10 @@ export class CoreBlockComponent implements OnInit, OnDestroy, DoCheck {
     @Input() block!: CoreCourseBlock; // The block to render.
     @Input() contextLevel!: string; // The context where the block will be used.
     @Input() instanceId!: number; // The instance ID associated with the context level.
-    @Input() extraData: any; // Any extra data to be passed to the block.
+    @Input() extraData!: Record<string, unknown>; // Any extra data to be passed to the block.
 
     componentClass?: Type<unknown>; // The class of the component to render.
-    data: any = {}; // Data to pass to the component.
+    data: Record<string, unknown> = {}; // Data to pass to the component.
     class?: string; // CSS class to apply to the block.
     loaded = false;
 
diff --git a/src/core/services/navigator.ts b/src/core/services/navigator.ts
index c5e380113..d543aac00 100644
--- a/src/core/services/navigator.ts
+++ b/src/core/services/navigator.ts
@@ -309,6 +309,7 @@ export class CoreNavigatorService {
      * @return Value of the parameter, undefined if not found.
      */
     getRouteParam<T = unknown>(name: string, routeOptions: CoreNavigatorCurrentRouteOptions = {}): T | undefined {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
         let value: any;
 
         if (!routeOptions.params) {
diff --git a/src/types/angular.d.ts b/src/types/angular.d.ts
index ab158dc8c..4f63bb656 100644
--- a/src/types/angular.d.ts
+++ b/src/types/angular.d.ts
@@ -19,6 +19,7 @@ declare module '@ionic/angular' {
 
     export class NavController {
 
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
         navigateForward(url: string | UrlTree | any[], options?: NavigationOptions): Promise<boolean | null>;
 
     }