Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/apps_/richdocuments/lib/Migration/Version30717Date20210310164901.php:15 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/apps_/richdocuments/lib/Migration/Version30717Date20210310164901.php on line 15