Can you make a test account for use to try?

I tried every link I could in the forums and could not get the internal error to come up. If I had to guess I would say it is a problem with your webhost. I've never seen an internal error like that when using PHP-Nuke.

If you can duplicate the error, write down the exact time it happens, then let your webhost know the exact time and maybe they can check the Apache weserver logs to see more detail unless you have access to those logs yourself.