Fatal error: Uncaught Error: Class "Sabre\DAV\Collection" not found in /home/ternalis/agenda/vendor/sabre/dav/lib/CalDAV/Schedule/Inbox.php:20 Stack trace: #0 {main} thrown in /home/ternalis/agenda/vendor/sabre/dav/lib/CalDAV/Schedule/Inbox.php on line 20