Cannot start artisan serve in laravel 5

I am using laravel 5, when I try to start server from

php artisan serve

I get following error :

[Symfony\Component\Debug\Exception\FatalErrorException] App\Providers\RouteServiceProvider::App\Providers{closure}(): Failed opening required 'D:\Test\app\app\Http/routes.php' (include_path='.;C:\xampp\php\pear')

I tried composer dump-autoload, it was successfull, but when i do

composer update

I get the same error.

How to resolve it?

via Chebli Mohamed