Fatal error: Uncaught Error: Class "yii\db\Migration" not found in /users/quirl/www/filemanager/spark/protected/runtime/module_backups/custom_pages_1728508006/migrations/m190213_135903_humhub_richtext_content.php:9 Stack trace: #0 {main} thrown in /users/quirl/www/filemanager/spark/protected/runtime/module_backups/custom_pages_1728508006/migrations/m190213_135903_humhub_richtext_content.php on line 9