Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /var/www/html/nextcloud/apps/files_external/lib/Migration/Version22000Date20210216084416.php:19 Stack trace: #0 {main} thrown in /var/www/html/nextcloud/apps/files_external/lib/Migration/Version22000Date20210216084416.php on line 19