Fatal error: Uncaught Error: Call to undefined function add_action() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-bookings/includes/class-ajax.php:11 Stack trace: #0 /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-bookings/includes/class-ajax.php(137): evobo_ajax->__construct() #1 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-bookings/includes/class-ajax.php on line 11