Fatal error: Uncaught Error: Interface "Sabre\CardDAV\Backend\BackendInterface" not found in C:\Apache24\htdocs\dle\engine\classes\composer\vendor\sabre\dav\lib\CardDAV\Backend\SyncSupport.php:23 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\dle\engine\classes\composer\vendor\sabre\dav\lib\CardDAV\Backend\SyncSupport.php on line 23