Fatal error: Uncaught Error: Class "Sabre\VObject\FreeBusyGenerator" not found in /var/www/html/nextcloud/apps/dav/lib/CalDAV/FreeBusy/FreeBusyGenerator.php:17 Stack trace: #0 {main} thrown in /var/www/html/nextcloud/apps/dav/lib/CalDAV/FreeBusy/FreeBusyGenerator.php on line 17