I need to call and action from another one. So, I use
Yii::$app->runAction('controller/existing-action');
but it returns a blank page.
If I use:
Yii::$app->runAction('controller/non-exists-action');
Yii2 throws error 404 not found. So, ‘existing-action’ is a valid call.
Therefore, why on the first case I get a blank page?