Im willing to bet something just didnt get formatted correctly syntax wise during the update. most likely just a silly error in code somewhere, a mistyped reference or something. Either that or its some epic fucking issue that requires an entire site redesign.
Its always like that with these things, there is no middle ground
I tried it, and i think it may be a problem with the search button in the menu bar. If you just hit reload when you get that error, it loads the full advanced search page, which seems to work fine.