Laravel Error on error page

I have installed the latest version of the Laravel 5.4 (before I worked with 4.2). Everything works perfect, but when I make a mistake in my application (eg. I use a class from another namespace without "use" at the beginning of the document), Laravel displays following error:

(1/1) InvalidArgumentException | The "" directory does not exist.

instead of the correct error. I think the correct error page doesn't display correctly and here is why this happens.

I tried to run:

$ composer install
$ composer composer dump-autoload

But the error still appears.

via Chebli Mohamed