[Imperial Fritz]

OK. I looked again over the install and obviously I thought it will do the replacements on its own. So I did them and all worked. You should make it clear that these replacements have to be done by hand and place on a visible spot what file needs to be edited.

And I still get the errors with devbox_work.php

EDIT:

I think I found the problem - it's in us trying to open devbox_work.php as a page, whereas it's actually just a collection of functions that get included in the index.php page. There is no way it can be viewed separately. To change the settings you manually edit it and reupload it.