Fatal error: Uncaught Error: Class "OCP\Migration\SimpleMigrationStep" not found in /home/tzuovhm/tzuovhm/core_/Migrations/Version18000Date20190920085628.php:18 Stack trace: #0 {main} thrown in /home/tzuovhm/tzuovhm/core_/Migrations/Version18000Date20190920085628.php on line 18