Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/core_/Migrations/Version13000Date20170718121200.php:14 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/core_/Migrations/Version13000Date20170718121200.php on line 14