Fatal error: Uncaught Error: Call to undefined function add_filter() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/UberMenu_StickyMenuExtension_3_1/includes/functions.php:3 Stack trace: #0 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/UberMenu_StickyMenuExtension_3_1/includes/functions.php on line 3