This error seems to indicate a general problem with your IIS setup, rather than a problem with FoxWeb. What happens if you try to get a simple (non-FoxWeb) page from your site? How about an .asp and an .aspx page?

 

Try searching for "HTTP Error 500.21" and you will find quite a few instances of people having this problem. The cause seems to be related to the ManagedPipelineHandler, but there are several causes. I suggest that you try the remedies recommended in each case.

 

You could check out the following article for some background information:

 

Regards,