*Currently* in a badly broken state. Rated 3 out of 5 stars
The add-on version showed me a bunch of JS errors as well, related to a library.
I would recommend the Greasemonkey version. But right now, it completely hangs my browser. :/
But don’t get me wrong: Most of the time, the Greasemonkey version worked nearly completely.
It is a dirty spaghetti solution though, that not only breaks every time something on FB is changed, but often doesn’t fix it in a very non-hackish way.
The former is not exactly the developer’s fault though. It’s the only choice one has.
So in general, I’ll simply install an older version of the Greasemonkey script, and not upgrade, until this mess is over.
Could you tell me the JS errors you get? Have you updated to the latest version 6.6? Or try installing directly from http://SocialFixer.com which may give better results.
Facebook just made a bunch more code changes, and I need to update my code to catch up. This happens from time to time, and it's just the nature of the beast!