Fatal error: Uncaught Error: Call to undefined function add_action() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/ubermenu/pro/sandbox/sandbox.php:8 Stack trace: #0 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/ubermenu/pro/sandbox/sandbox.php on line 8