To add a little more information, I checked my site with Sucuri’s site checker, and it received the same 404 error. I’ve also examined my .htaccess, index.php, header and footer.phps, and several other files, and could not find any code that looked suspicious. I’m something of a neophyte on things like this, however, so I really don’t know where to look, or what I would have to do to fix this problem.
I would be happy to provide any further details that I can, and any assistance or advice on this issue would be enormously appreciated.