Fatal error: Uncaught Error: Class "ilAppointmentBaseFileHandler" not found in /var/www/html/ilias/components/ILIAS/Calendar/classes/FileHandler/class.ilAppointmentSessionFileHandler.php:14 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Calendar/classes/FileHandler/class.ilAppointmentSessionFileHandler.php on line 14