The following has been appearing a lot in my chat log in Pandaria Remix:

HandyNotes _Achieverents Error: ...
HandyNotes Achievements/
HandyNotes Achievements.lua:378: attempt to call global
"'GetFactionInfoByID' (a nil value)

I don't know what is causing it... and I don't know why BugSack/BugGrabber doesn't catch it. But it has been appearing for the last several days.

The same issue with the last updates of the game.