Fatal error: Uncaught Error: Call to undefined function add_filter() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/ubermenu/pro/admin/custom.menu-item-types.pro.php:3 Stack trace: #0 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/ubermenu/pro/admin/custom.menu-item-types.pro.php on line 3