Lost my connection to "configuration" in drupal.

Hi
I try to Upgrade my drupal and it looks fine in the start but when I go to “configuration” as admin I get a Message: failure in this site.
the command is: /admin/config.php

If I change to /admin/web.config.php
I got to the administration site.

I don’t now where I can look for failure in this site.

( have try in to days.. 🙂 )

Kjell

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/21/feed