diff --git a/apps/theming/lib/Service/ThemesService.php b/apps/theming/lib/Service/ThemesService.php
index d7127173848bb..fba63923a2088 100644
--- a/apps/theming/lib/Service/ThemesService.php
+++ b/apps/theming/lib/Service/ThemesService.php
@@ -164,8 +164,7 @@ public function isEnabled(ITheme $theme): bool {
 	}
 
 	/**
-	 * Get the list of all enabled themes IDs
-	 * for the logged-in user
+	 * Get the list of all enabled themes IDs for the current user.
 	 *
 	 * @return string[]
 	 */
diff --git a/cypress/e2e/core/404-error.cy.ts b/cypress/e2e/core/404-error.cy.ts
new file mode 100644
index 0000000000000..b24562933e8bb
--- /dev/null
+++ b/cypress/e2e/core/404-error.cy.ts
@@ -0,0 +1,19 @@
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+describe('404 error page', { testIsolation: true }, () => {
+	it('renders 404 page', () => {
+		cy.visit('/doesnotexist', { failOnStatusCode: false })
+
+		cy.findByRole('heading', { name: /Page not found/ })
+			.should('be.visible')
+		cy.findByRole('link', { name: /Back to Nextcloud/ })
+			.should('be.visible')
+			.click()
+
+		cy.url()
+			.should('match', /(\/index.php)\/login$/)
+	})
+})
diff --git a/lib/private/TemplateLayout.php b/lib/private/TemplateLayout.php
index 5d29b06a73b8f..7d7002c71dbc9 100644
--- a/lib/private/TemplateLayout.php
+++ b/lib/private/TemplateLayout.php
@@ -112,13 +112,6 @@ public function __construct($renderAs, $appId = '') {
 			} else {
 				Util::addScript('core', 'unified-search', 'core');
 			}
-			// Set body data-theme
-			$this->assign('enabledThemes', []);
-			if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
-				/** @var \OCA\Theming\Service\ThemesService */
-				$themesService = \OC::$server->get(\OCA\Theming\Service\ThemesService::class);
-				$this->assign('enabledThemes', $themesService->getEnabledThemes());
-			}
 
 			// Set logo link target
 			$logoUrl = $this->config->getSystemValueString('logo_url', '');
@@ -183,8 +176,6 @@ public function __construct($renderAs, $appId = '') {
 			if ($user) {
 				$userDisplayName = $user->getDisplayName();
 			}
-			$theme = $this->config->getSystemValueString('enforce_theme', '');
-			$this->assign('enabledThemes', $theme === '' ? [] : [$theme]);
 			$this->assign('user_displayname', $userDisplayName);
 			$this->assign('user_uid', \OC_User::getUser());
 		} elseif ($renderAs === TemplateResponse::RENDER_AS_PUBLIC) {
@@ -192,14 +183,6 @@ public function __construct($renderAs, $appId = '') {
 			$this->assign('appid', $appId);
 			$this->assign('bodyid', 'body-public');
 
-			// Set body data-theme
-			$this->assign('enabledThemes', []);
-			if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
-				/** @var \OCA\Theming\Service\ThemesService $themesService */
-				$themesService = \OC::$server->get(\OCA\Theming\Service\ThemesService::class);
-				$this->assign('enabledThemes', $themesService->getEnabledThemes());
-			}
-
 			// Set logo link target
 			$logoUrl = $this->config->getSystemValueString('logo_url', '');
 			$this->assign('logoUrl', $logoUrl);
@@ -227,9 +210,14 @@ public function __construct($renderAs, $appId = '') {
 		} else {
 			parent::__construct('core', 'layout.base');
 		}
-		// Send the language and the locale to our layouts
-		$lang = \OC::$server->getL10NFactory()->findLanguage();
-		$locale = \OC::$server->getL10NFactory()->findLocale($lang);
+
+		// Set body data-theme
+		$themesService = \OCP\Server::get(\OCA\Theming\Service\ThemesService::class);
+		$this->assign('enabledThemes', $themesService->getEnabledThemes());
+
+		// Send the language, locale, and direction to our layouts
+		$lang = \OC::$server->get(IFactory::class)->findLanguage();
+		$locale = \OC::$server->get(IFactory::class)->findLocale($lang);
 
 		$lang = str_replace('_', '-', $lang);
 		$this->assign('language', $lang);