diff --git a/scripts/langindex.json b/scripts/langindex.json
index 7e8e452d6..5dd3147e9 100644
--- a/scripts/langindex.json
+++ b/scripts/langindex.json
@@ -2194,6 +2194,8 @@
   "core.login.stillcantconnect": "local_moodlemobileapp",
   "core.login.supplyinfo": "moodle",
   "core.login.toggleremove": "local_moodlemobileapp",
+  "core.login.unsupportedsite": "local_moodlemobileapp",
+  "core.login.unsupportedsitemessage": "local_moodlemobileapp",
   "core.login.username": "moodle",
   "core.login.usernamelowercase": "moodle",
   "core.login.usernameoremail": "moodle",
diff --git a/src/core/features/login/constants.ts b/src/core/features/login/constants.ts
index 0da8f8fe3..b83fbe9d6 100644
--- a/src/core/features/login/constants.ts
+++ b/src/core/features/login/constants.ts
@@ -21,3 +21,6 @@ export const EMAIL_SIGNUP_FEATURE_NAME = 'CoreLoginEmailSignup';
 export const FORGOTTEN_PASSWORD_FEATURE_NAME = 'NoDelegate_ForgottenPassword';
 export const IDENTITY_PROVIDERS_FEATURE_NAME = 'NoDelegate_IdentityProviders';
 export const IDENTITY_PROVIDER_FEATURE_NAME_PREFIX = 'NoDelegate_IdentityProvider_';
+
+// Event indicating that a user left the app because it wasn't supported by a site.
+export const APP_UNSUPPORTED_CHURN = 'app_unsupported_churn';
diff --git a/src/core/features/login/lang.json b/src/core/features/login/lang.json
index edbf0c44c..a3b4e91e8 100644
--- a/src/core/features/login/lang.json
+++ b/src/core/features/login/lang.json
@@ -119,6 +119,8 @@
     "stillcantconnect": "Still can't connect?",
     "supplyinfo": "More details",
     "toggleremove": "Edit accounts list",
+    "unsupportedsite": "Site not accessible through the app",
+    "unsupportedsitemessage": "{{site}} can't be accessed through this app.\nYou can still access it using a web browser",
     "username": "Username",
     "usernamelowercase": "Only lowercase letters allowed",
     "usernameoremail": "Enter either username or email address",
diff --git a/src/core/features/login/pages/credentials/credentials.ts b/src/core/features/login/pages/credentials/credentials.ts
index 2bef573d0..2f936c812 100644
--- a/src/core/features/login/pages/credentials/credentials.ts
+++ b/src/core/features/login/pages/credentials/credentials.ts
@@ -35,6 +35,7 @@ import { CorePlatform } from '@services/platform';
 import { CoreSitesFactory } from '@services/sites-factory';
 import { EMAIL_SIGNUP_FEATURE_NAME, FORGOTTEN_PASSWORD_FEATURE_NAME } from '@features/login/constants';
 import { CoreCustomURLSchemes } from '@services/urlschemes';
+import { CoreSiteError } from '@classes/errors/siteerror';
 
 /**
  * Page to enter the user credentials.
@@ -292,7 +293,11 @@ export class CoreLoginCredentialsPage implements OnInit, OnDestroy {
 
             await CoreNavigator.navigateToSiteHome({ params: { urlToOpen: this.urlToOpen } });
         } catch (error) {
-            CoreLoginHelper.treatUserTokenError(siteUrl, error, username, password);
+            if (error instanceof CoreSiteError && CoreLoginHelper.isAppUnsupportedError(error)) {
+                await CoreLoginHelper.showAppUnsupportedModal(siteUrl, this.site, error.debug);
+            } else {
+                CoreLoginHelper.treatUserTokenError(siteUrl, error, username, password);
+            }
 
             if (error.loggedout) {
                 CoreNavigator.navigate('/login/sites', { reset: true });
diff --git a/src/core/features/login/pages/site/site.ts b/src/core/features/login/pages/site/site.ts
index 9cabf031a..64f6eaa9d 100644
--- a/src/core/features/login/pages/site/site.ts
+++ b/src/core/features/login/pages/site/site.ts
@@ -48,6 +48,7 @@ import { CorePlatform } from '@services/platform';
 import { CoreReferrer } from '@services/referrer';
 import { CoreSitesFactory } from '@services/sites-factory';
 import { ONBOARDING_DONE } from '@features/login/constants';
+import { CoreUnauthenticatedSite } from '@classes/sites/unauthenticated-site';
 
 /**
  * Site (url) chooser when adding a new site.
@@ -301,7 +302,7 @@ export class CoreLoginSitePage implements OnInit {
         url = url.trim();
 
         if (url.match(/^(https?:\/\/)?campus\.example\.edu/)) {
-            this.showLoginIssue(null, new CoreError(Translate.instant('core.login.errorexampleurl')));
+            this.showLoginIssue(url, new CoreError(Translate.instant('core.login.errorexampleurl')));
 
             return;
         }
@@ -403,17 +404,23 @@ export class CoreLoginSitePage implements OnInit {
      * @param url The URL the user was trying to connect to.
      * @param error Error to display.
      */
-    protected async showLoginIssue(url: string | null, error: CoreError): Promise<void> {
+    protected async showLoginIssue(url: string, error: CoreError): Promise<void> {
         let errorMessage = CoreDomUtils.getErrorMessage(error);
-        let siteExists = false;
-        let supportConfig: CoreUserSupportConfig | undefined = undefined;
-        let errorTitle: string | undefined;
         let debug: CoreSiteErrorDebug | undefined;
+        let errorTitle: string | undefined;
+        let site: CoreUnauthenticatedSite | undefined;
+        let supportConfig: CoreUserSupportConfig | undefined;
 
         if (error instanceof CoreSiteError) {
             supportConfig = error.supportConfig;
-            siteExists = supportConfig instanceof CoreUserGuestSupportConfig;
+            site = supportConfig instanceof CoreUserGuestSupportConfig ? supportConfig.getSite() : undefined;
             debug = error.debug;
+
+            if (CoreLoginHelper.isAppUnsupportedError(error)) {
+                await CoreLoginHelper.showAppUnsupportedModal(url, site, debug);
+
+                return;
+            }
         }
 
         if (error instanceof CoreLoginError) {
@@ -440,7 +447,7 @@ export class CoreLoginSitePage implements OnInit {
                     }),
                 }
                 : (
-                    !siteExists
+                    !site
                         ? {
                             text: Translate.instant('core.needhelp'),
                             cssClass: 'core-login-need-help',
diff --git a/src/core/features/login/services/login-helper.ts b/src/core/features/login/services/login-helper.ts
index 22bb66755..09b6cd7e0 100644
--- a/src/core/features/login/services/login-helper.ts
+++ b/src/core/features/login/services/login-helper.ts
@@ -48,6 +48,7 @@ import {
     TypeOfLogin,
 } from '@classes/sites/unauthenticated-site';
 import {
+    APP_UNSUPPORTED_CHURN,
     EMAIL_SIGNUP_FEATURE_NAME,
     FAQ_QRCODE_IMAGE_HTML,
     FAQ_QRCODE_INFO_DONE,
@@ -56,6 +57,7 @@ import {
     IDENTITY_PROVIDER_FEATURE_NAME_PREFIX,
 } from '../constants';
 import { LazyRoutesModule } from '@/app/app-routing.module';
+import { CoreSiteError, CoreSiteErrorDebug } from '@classes/errors/siteerror';
 
 /**
  * Helper provider that provides some common features regarding authentication.
@@ -65,6 +67,15 @@ export class CoreLoginHelperProvider {
 
     protected static readonly PASSWORD_RESETS_CONFIG_KEY = 'password-resets';
 
+    private static readonly APP_UNSUPPORTED_ERRORS = [
+        'loginfailed',
+        'logintokenempty',
+        'logintokenerror',
+        'mobileservicesnotenabled',
+        'sitehasredirect',
+        'webservicesnotenabled',
+    ];
+
     protected logger: CoreLogger;
     protected sessionExpiredCheckingSite: Record<string, boolean> = {};
     protected isOpenEditAlertShown = false;
@@ -930,11 +941,61 @@ export class CoreLoginHelperProvider {
         return String(CoreConstants.CONFIG.skipssoconfirmation) === 'true';
     }
 
+    /**
+     * Check whether the given error means that the app is not working in the site.
+     *
+     * @param error Site error.
+     * @returns Whether the given error means that the app is not working in the site.
+     */
+    isAppUnsupportedError(error: CoreSiteError): boolean {
+        return CoreLoginHelperProvider.APP_UNSUPPORTED_ERRORS.includes(error.debug?.code ?? '');
+    }
+
+    /**
+     * Show modal indicating that the app is not supported in the site.
+     *
+     * @param siteUrl Site url.
+     * @param site Site instance.
+     * @param debug Error debug information.
+     */
+    async showAppUnsupportedModal(siteUrl: string, site?: CoreUnauthenticatedSite, debug?: CoreSiteErrorDebug): Promise<void> {
+        const siteName = await site?.getSiteName() ?? siteUrl;
+
+        await CoreDomUtils.showAlertWithOptions({
+            header: Translate.instant('core.login.unsupportedsite'),
+            message: Translate.instant('core.login.unsupportedsitemessage', { site: siteName }),
+            buttons: [
+                {
+                    text: Translate.instant('core.cancel'),
+                    role: 'cancel',
+                },
+                {
+                    text: Translate.instant('core.openinbrowser'),
+                    handler: () => this.openInBrowserFallback(site?.getURL() ?? siteUrl, debug),
+                },
+            ],
+        });
+    }
+
+    /**
+     * Open site in browser as fallback when it is not supported in the app.
+     *
+     * @param siteUrl Site url.
+     * @param debug Error debug information.
+     */
+    async openInBrowserFallback(siteUrl: string, debug?: CoreSiteErrorDebug): Promise<void> {
+        CoreEvents.trigger(APP_UNSUPPORTED_CHURN, { siteUrl, debug });
+
+        await CoreUtils.openInBrowser(siteUrl, { showBrowserWarning: false });
+    }
+
     /**
      * Show a modal warning that the credentials introduced were not correct.
      */
-    protected showInvalidLoginModal(error: CoreWSError): void {
-        CoreDomUtils.showErrorModal(error.message);
+    protected showInvalidLoginModal(error: CoreError): void {
+        const errorDetails = error instanceof CoreSiteError ? error.debug?.details : null;
+
+        CoreDomUtils.showErrorModal(errorDetails ?? error.message);
     }
 
     /**
@@ -1074,8 +1135,10 @@ export class CoreLoginHelperProvider {
      * @param username Username.
      * @param password User password.
      */
-    treatUserTokenError(siteUrl: string, error: CoreWSError, username?: string, password?: string): void {
-        switch (error.errorcode) {
+    treatUserTokenError(siteUrl: string, error: CoreError, username?: string, password?: string): void {
+        const errorCode = 'errorcode' in error ? error.errorcode : null;
+
+        switch (errorCode) {
             case 'forcepasswordchangenotice':
                 this.openChangePassword(siteUrl, CoreTextUtils.getErrorMessageFromError(error) ?? '');
                 break;
@@ -1617,3 +1680,16 @@ export type CoreLoginSiteFinderSettings = {
     displayurl: boolean;
     defaultimageurl?: string;
 };
+
+declare module '@singletons/events' {
+
+    /**
+     * Augment CoreEventsData interface with events specific to this service.
+     *
+     * @see https://www.typescriptlang.org/docs/handbook/declaration-merging.html#module-augmentation
+     */
+    export interface CoreEventsData {
+        [APP_UNSUPPORTED_CHURN]: { siteUrl: string; debug?: CoreSiteErrorDebug };
+    }
+
+}
diff --git a/src/core/features/login/tests/behat/basic_usage.feature b/src/core/features/login/tests/behat/basic_usage.feature
index 46bc64d17..b0eb396ad 100755
--- a/src/core/features/login/tests/behat/basic_usage.feature
+++ b/src/core/features/login/tests/behat/basic_usage.feature
@@ -47,6 +47,16 @@ Feature: Test basic usage of login in app
     And I press "Connect to your site" in the app
     Then I should find "Can't connect to site" in the app
 
+  Scenario: Attempt invalid login
+    When I launch the app
+    And I set the field "Your site" to "$WWWROOT" in the app
+    And I press "Connect to your site" in the app
+    And I set the following fields to these values in the app:
+      | Username | student1      |
+      | Password | wrongpassword |
+    And I press "Log in" near "Lost password?" in the app
+    Then I should find "Invalid login" in the app
+
   Scenario: Add a non existing account from accounts switcher
     Given I entered the app as "student1"
     And I press the user menu button in the app
diff --git a/src/core/features/user/classes/support/guest-support-config.ts b/src/core/features/user/classes/support/guest-support-config.ts
index a21c7c030..f60277e0d 100644
--- a/src/core/features/user/classes/support/guest-support-config.ts
+++ b/src/core/features/user/classes/support/guest-support-config.ts
@@ -71,6 +71,15 @@ export class CoreUserGuestSupportConfig extends CoreUserSupportConfig {
         return 'supportpage' in this.config;
     }
 
+    /**
+     * Get site.
+     *
+     * @returns site.
+     */
+    getSite(): CoreUnauthenticatedSite {
+        return this.site;
+    }
+
     /**
      * @inheritdoc
      */