Yeah, Taylor made some major changes in the past week or so. You might wanna go over them and update your files accordingly.

https://github.com/laravel/laravel/commits/develop

In my case I did the following: Open app/Providers/RouteServiceProvider.php and update the line 37 from:

$this->namespaced( function(Router $router) {
  //some stuff
}

to:

$this->namespaced("App\\Http\\Controllers", function(Router $router) {
  //same stuff
}

or according to the current directory structure if you changed it.

I have the same problem, config/namespace.php was remove, and I cannot access to the "namespace" config, and some packages also don't work with that change.