It seems i forgot to add the new 'expire_on_close' => false, into the 'app/config/session.php' file.

Now, I'm getting this error: Class 'Illuminate\Routing\Controllers\Controller' not found

Appearently the Controller.php file has been moved to "Illuminate\Routing\Controller" and is no longer in it's own dir.

How can I fix this?...

Did you even read the upgrade guide? This is all documented.

http://laravel.com/docs/upgrade#upgrade-4.1

Make sure you click 4.1 in the upper right corner.

Hm, I'm gonna try it again, I probably missed some parts of the upgrade procedure.

Ok, I just did it. I'm still getting the same error "Class 'Illuminate\Routing\Controllers\Controller' not found".

I'm pretty sure I followed the upgrade guide completely.

What do you mean by... I just changed the app/config/*.php files, not for all my environments.?