Fatal error: Uncaught Error: Interface 'Sabre\CalDAV\ICalendarObject' not found in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/Schedule/ISchedulingObject.php:11 Stack trace: #0 {main} thrown in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/Schedule/ISchedulingObject.php on line 11