Fatal error: Uncaught Error: Class "yii\db\Migration" not found in /var/www/html/prod/vendor/yiisoft/yii2/rbac/migrations/m140506_102106_rbac_init.php:17 Stack trace: #0 {main} thrown in /var/www/html/prod/vendor/yiisoft/yii2/rbac/migrations/m140506_102106_rbac_init.php on line 17