Fatal error: Uncaught Error: Call to undefined function add_action() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-rsvp/includes/admin/class-settings.php:9 Stack trace: #0 /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-rsvp/includes/admin/class-settings.php(320): EVORS_Settings->__construct() #1 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-rsvp/includes/admin/class-settings.php on line 9