November 4, 2009
Apparently Facebook made some changes to their chat interface without warning anyone. The Adium blog reports that the plugin’s Author is working on the problem but currently no ETA.
They also suggest sending Facebook feedback about this issue and even provide a handy link to Facebook to vent frustrations.
Some fixes tried have been to remove and re-add the Facebook account, delete the Adium account preference file, and to pre-sign in to Facebook via the web interface.
All of these have failed to work permanently.