Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/apps_/activity/lib/Migration/Version2010Date20190416112817.php:18 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/apps_/activity/lib/Migration/Version2010Date20190416112817.php on line 18