Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/apps/activity/lib/Migration/Version2006Date20170808155040.php:13 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/apps/activity/lib/Migration/Version2006Date20170808155040.php on line 13