Fatal error: Uncaught Error: Class "Sabre\DAV\ServerPlugin" not found in D:\xampp\htdocs\pimcore\my-project\vendor\sabre\dav\lib\CalDAV\Plugin.php:31 Stack trace: #0 {main} thrown in D:\xampp\htdocs\pimcore\my-project\vendor\sabre\dav\lib\CalDAV\Plugin.php on line 31