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Message: Interface\AddOns\wg\wg.lua:15: Usage: UnitBuff("unit", [index] or ["name", "rank"][, "filter"])
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This is the problem in ur Lua code. shows the line and location and whats wrong with it. in this case ur not using UnitBuff properly.
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Locals: (*temporary) = "player"
(*temporary) = nil
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looks like u've manage to include the first argument of the function but theres something going in the second argument. ((someone correct me if im wrong))