When a player leaves or joins the raid in combat, Blizzard Raid Frames can get messed up badly. Blizzard Raid Interface Antidote is here to fix this problem efficiently. The player won't even notice that the AddOn is running.
What it does
Frames refering to units no longer available (i.e: a player left the group) but that can't be hidden because you are still in combat will be greyed out.
Blizzard Raid Interface Antidote delays Blizzard Raid Frames attempts to create/rearrange/hide frames during combat (which fail by design since you are in combat...).
The frames are then created/rearranged/hidden upon leaving combat.
You will still be unable to see the frame of a player that joins the group until you leave combat.
You will still have "leftover" frames until you leave combat, but at least these will be clearly displayed as such.
This AddOn should be compatible with all languages.