Quote from ElsiaI get errors whenever a hunter gets invited to the party. Unfortunately I missed to copy it, will do next time it happens. One frame, though not necessarily the hunter's will not show. A reloadui fixes the problem without errors.
The error wasn't one within ag though and the trace did not lead it back to aguf. The error was within one of Blizzards UI templates.
Sorry for this not being as specific as it should be. I'll post details when I get a second chance.
Okay, there is a bug in the blizzard secure header code, which breaks all unit frame addons.
If party member #2-4 joins while you're in combat, you will get an error pointing to line 511 in SecureHandlers.lua.
It can be reproduced easily, with the following code:
local header = CreateFrame("Button","TestHeader",UIParent,"SecurePartyHeaderTemplate")
header.initialConfigFunction = function(frame) ChatFrame1:AddMessage(frame:GetName()) end
Hopefully this will get fixed soon, because it is annoying for everyone who uses and writes addon unit frames.