I just noticed that this thread does not have the correct solution posted yet.
The following encounters use a special form of possessbar:
- Blackwing Descent, Nefarian encounter
- Feast Fest
- Heart of Fear, Un'Sok encounter
By default those spells for a possessed player will be displayed in the MainMenuActionBar.
But...sometimes Blizzard thinks it's funnier to plump you in a Vehicle without telling anyone. Not even the own API. Thus neither [overridebar] nor [vehicleui] wil fire. (Which is a bug imo).
The solution is to use a third condition checking for possessbar state while in a vehicle.
Lua Code:
[possessbar,@vehicle,exists]
Implementation:
http://code.google.com/p/rothui/sour...ar.lua&old=945