Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/core/Migrations/Version13000Date20170814074715.php:12 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/core/Migrations/Version13000Date20170814074715.php on line 12