Fatal error: Uncaught Error: Class 'Sabre\DAV\ServerPlugin' not found in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/SharingPlugin.php:26 Stack trace: #0 {main} thrown in /home/malert/WebDAV/vendor/sabre/dav/lib/CalDAV/SharingPlugin.php on line 26