So last night, the web hosting company I use decided to make some server upgrades without advance notice. That caused some things around the site to break due to software incompatibilities.
I think everything is fixed now - but it's entirely possible I missed something. If you encounter any error messages when using the site, please let me know so I can look into it. I'll need to know which page you saw the error on - if I can find the same page, I should be able to see it and go from there.