Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/apps/activity/lib/Migration/Version2011Date20201006132547.php:15 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/apps/activity/lib/Migration/Version2011Date20201006132547.php on line 15