Fatal error: Uncaught Error: Interface "Sabre\DAV\Auth\Backend\BackendInterface" not found in /var/www/html/nextcloud/apps/photos/lib/Sabre/PublicAlbumAuthBackend.php:13 Stack trace: #0 {main} thrown in /var/www/html/nextcloud/apps/photos/lib/Sabre/PublicAlbumAuthBackend.php on line 13