setViewsDir and forward

I use namespaces. I have a "App\Controllers" and "App\Controllers\Admin". Inside the controller "App\Controllers\Admin\ControllerBase" I have done so:

public function afterExecuteRoute() {
    $this->view->setViewsDir($this->view->getViewsDir().'admin/');
    }

And it works, but when I do so inside the controller "App\Controllers\Admin\IndexController": $this->dispatcher->forward(array("controller" => "error", "action" => "notFound"));, I see a blank page. But if within the "App\Controllers\Admin\ErrorController" I quote the following: $this->view->setViewsDir(__DIR__."/../../views/"); all works. Why do I have to change the directory to "view"? Why not work with a directory "view/admin"?

P.S.: Sorry for my terrible english.