Fatal error: Uncaught Error: Call to undefined function add_filter() in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-daily-repeats/eventon-daily-repeats.php:22 Stack trace: #0 /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-daily-repeats/eventon-daily-repeats.php(110): EventON_daily_repeats->__construct() #1 {main} thrown in /users/laufgruppe-lvb/www/wordpress/wp-content/plugins/eventon-daily-repeats/eventon-daily-repeats.php on line 22