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