Fatal error: Uncaught Error: Interface 'Sabre\CalDAV\Xml\Notification\NotificationInterface' not found in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/Xml/Notification/Invite.php:20 Stack trace: #0 {main} thrown in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/Xml/Notification/Invite.php on line 20