diff --git a/index.php b/index.php
index 482d9fe84330..201a21aa5183 100644
--- a/index.php
+++ b/index.php
@@ -49,18 +49,22 @@
 	OC::handleRequest();
 
 } catch(\OC\ServiceUnavailableException $ex) {
+	\OC::loadDefaultEnabledAppTheme();
 	\OC::$server->getLogger()->logException($ex, array('app' => 'index'));
 
 	//show the user a detailed error page
 	OC_Response::setStatus(OC_Response::STATUS_SERVICE_UNAVAILABLE);
 	OC_Template::printExceptionErrorPage($ex);
 } catch (\OC\HintException $ex) {
+	\OC::loadDefaultEnabledAppTheme();
 	OC_Response::setStatus(OC_Response::STATUS_SERVICE_UNAVAILABLE);
 	OC_Template::printErrorPage($ex->getMessage(), $ex->getHint());
 } catch (\OC\User\LoginException $ex) {
+	\OC::loadDefaultEnabledAppTheme();
 	OC_Response::setStatus(OC_Response::STATUS_FORBIDDEN);
 	OC_Template::printErrorPage($ex->getMessage());
 } catch (Exception $ex) {
+	\OC::loadDefaultEnabledAppTheme();
 	try {
 		\OC::$server->getLogger()->logException($ex, array('app' => 'index'));
 
@@ -76,6 +80,7 @@
 		echo('</body></html>');
 	}
 } catch (Error $ex) {
+	\OC::loadDefaultEnabledAppTheme();
 	\OC::$server->getLogger()->logException($ex, array('app' => 'index'));
 	OC_Response::setStatus(OC_Response::STATUS_INTERNAL_SERVER_ERROR);
 	OC_Template::printExceptionErrorPage($ex);
diff --git a/lib/base.php b/lib/base.php
index 8fe7964fab63..4b55826811ec 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -825,6 +825,22 @@ protected static function registerAutoloaderCache() {
 		}
 	}
 
+	/**
+	 * Enables the defaultEnabled app theme
+	 * __do not__ call this for every request, as this parses all apps info.xml
+	 * files in order to determine which app is a default enabled theme while
+	 * not accessing the database which might not be available.
+	 */
+	public static function loadDefaultEnabledAppTheme() {
+		$defaultEnabledAppTheme = \OC_App::getDefaultEnabledAppTheme();
+
+		if ($defaultEnabledAppTheme !== false) {
+			/** @var \OC\Theme\ThemeService $themeService */
+			$themeService = \OC::$server->query('ThemeService');
+			$themeService->setAppTheme($defaultEnabledAppTheme);
+		}
+	}
+
 	/**
 	 * Handle the request
 	 */
@@ -843,13 +859,7 @@ public static function handleRequest() {
 				\OC::$server->getL10N('lib'), new \OC_Defaults(), \OC::$server->getLogger(),
 				\OC::$server->getSecureRandom());
 
-			$defaultEnabledAppTheme = \OC_App::getDefaultEnabledAppTheme();
-
-			if ($defaultEnabledAppTheme !== false) {
-				/** @var \OC\Theme\ThemeService $themeService */
-				$themeService = \OC::$server->query('ThemeService');
-				$themeService->setAppTheme($defaultEnabledAppTheme);
-			}
+			self::loadDefaultEnabledAppTheme();
 
 			$controller = new OC\Core\Controller\SetupController($setupHelper);
 			$controller->run($_POST);