First off, let me apologize for the site’s horrid layout. Do to upgrading, I had to pick one of the out-of-the-box WordPress themes. Hopefully I’ll have something a bit better up in the next day or so.
As mentioned, I just did upgrade WordPress, from 2.5.x to 3.7.1. Since you’re reading this, there’s a good chance that you also were doing something similar. If this is the case, and you haven’t already done so, I would suggest reading Upgrading WordPress – Extended Instructions over at Codex.