Not sure why, but when I upgraded to WordPress 3.8 Simple Local Avatars killed the site.
If I was logged out of the site, the site loaded fine. As soon as I logged in, I'd get a white screen on the frontend and backend and Chrome would say that there was no data returned.
I renamed the plugin via FTP (to disable it) and the site loaded just fine.
Not sure what's going on, but are there any known issues?