Fatal error: Uncaught Error: Class "Sabre\DAV\ServerPlugin" not found in /var/www/illumine/vendor/sabre/dav/lib/DAV/PartialUpdate/Plugin.php:23 Stack trace: #0 {main} thrown in /var/www/illumine/vendor/sabre/dav/lib/DAV/PartialUpdate/Plugin.php on line 23