Eliminating Author 404 errors in Evolve

I have started getting notifications of Author 404 errors in Evolve and don’t know how to stop them. I really don’t use a lot of blogs and wouldn’t assign an author if I didn’t have to do so. Any ideas of what plug-in that might be causing these errors or is there a central place in Evolve? [Note: if you suggest making PHP or CSS corrections, you’ll have to be very specific because I’m not very versed in going in and tweaking.]