I just installed YAF on DNN and added about 20 forums in 3 categories. However, when I (or any uses) clicks on the forum, they get the following message:

Server Error in '/' Application.

The resource cannot be found.

Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.

I added a new forum after this happened and it doesn't reproduce the error. I'm a little boggled. Is this fixable or do I have to start making forums from scratch again (and can this happen again if I do?)

I think I found my own answer. Any forums that had an "&" in their name were failing. Changing it to "and" seems to have fixed things.