[HOTFIX] Fix for empty menus causing exception

Classes/ViewHelpers/Menu/Controller/RenderController.php

@@ -45,7 +45,7 @@ class RenderController extends AbstractWidgetController
         /** @var Menu $menu */
         $menu = $this->menuRepository->findByIdentifier($this->widgetConfiguration['uid']);
 
-        if (!$this->widgetConfiguration['disableSecurityCheck']) {
+        if (!is_null($menu) && !$this->widgetConfiguration['disableSecurityCheck']) {
             $this->menuSecurityService->applySecurityCheck($menu);
         }