Mother of God I just spent hours trying to figure out why I couldn't publish a post I was writing…I kept getting a 404 error every time I tried to save or publish the post. So, I searched all over the place for an answer but to no avail. I poured through my server logs to find traces of a hacker, but again, no luck. Finally, I realized what it was…
While writing another post about the solution to another error in WordPress, I referenced the htaccess file, but with a period in front. Apparently mod_security has some sort of problem with that and wouldn't budget, so I had to leave out the period.
If you absolutely must include "htaccess," but starting with a period, in your post, I think they solved the problem by turning off mod_security here, although I don't think that's the smartest thing you can do.
