Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/core_/Migrations/Version15000Date20180926101451.php:16 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/core_/Migrations/Version15000Date20180926101451.php on line 16