Fatal error: Uncaught Error: Interface 'Sabre\DAV\IExtendedCollection' not found in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/CalendarHome.php:23 Stack trace: #0 {main} thrown in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/CalendarHome.php on line 23