I've upgraded the Dune site (in my signature) from 2.0.7.3, and now the forums stopped working. I see only an empty page, and when I try to go to a forum manually (via a link), I get this error:
ERROR: Could not connect to the forums database.
I checked the database, it seems like forum tables are still there. I can access the categories via the admin interface.
It annoyed that I had to open the code to see it is XOOPS - nothing is mentioned on the site, and the footer even says that all rights reserved to the company -http://demo.dotcom.co.il/