Fatal error: Uncaught Error: Interface "OCP\Migration\ISchemaMigration" not found in /usr/local/www/owncloud/apps/activity/appinfo/Migrations/Version20170724182159.php:13 Stack trace: #0 {main} thrown in /usr/local/www/owncloud/apps/activity/appinfo/Migrations/Version20170724182159.php on line 13