Fatal error: Uncaught Error: Interface "Sabre\Xml\Element" not found in /var/www/illumine/vendor/sabre/dav/lib/CalDAV/Xml/Property/ScheduleCalendarTransp.php:27 Stack trace: #0 {main} thrown in /var/www/illumine/vendor/sabre/dav/lib/CalDAV/Xml/Property/ScheduleCalendarTransp.php on line 27