Fatal error: Uncaught Error: Class "OCA\Files_External\Lib\Auth\AuthMechanism" not found in /var/www/html/nextcloud/apps/files_external/lib/Lib/Auth/OAuth2/OAuth2.php:16 Stack trace: #0 {main} thrown in /var/www/html/nextcloud/apps/files_external/lib/Lib/Auth/OAuth2/OAuth2.php on line 16