Authors not working with permalinks

Hello folks..

While using permalinks, I am having an issue with the author links – every other link works fine. The link would normally point to “/?author=4” of course, but after changing my permalink structure to “/%category%/%postname%” the author links bring up a 404 error. They are trying to access “/author/Mark/” and I’m not sure what the issue is, especially when every other link works fine within this environment.

I’ve searched online and in this forum, but I haven’t been able to find a clue as to what the problem is.