Fatal error: Uncaught Error: Call to undefined function add_action() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/clever-fox/inc/eduvert/features/eduvert-course-category.php:237 Stack trace: #0 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/clever-fox/inc/eduvert/features/eduvert-course-category.php on line 237