A few minutes ago I posted a reply in one of our forums, and got this error:

Error: 0 - Invalid controller: name='rating', format=''

I have never seen this before, but I DID update the CJlib today - so maybe it's some rare edge case related to that??

I hit the back button and reposted my reply, and it went through fine the second time. The reply was a one liner, no attachments, but included a URL inline. I was logged in with my usual super-admin account that I typically patrol our forums with...

nothing in joomla logs or php error logs