[pelf]

Originally Posted by Uitat local aspect = CreateFrame("Frame", nil, UIParent)         aspect:RegisterEvent("PLAYER_ENTERING_WORLD")         aspect:SetScript("OnEvent", function(self, event)             UIParent:SetScale(0.6)  -- you can change the scale here but you will break the entire add-on --             aspect:UnregisterAllEvents()         print ("Your Resolution Scale has been changed to 0.6") end)

The indentation you're using there is a bit confusing. Disregard this if that's due to pasting it onto a forum. I'd indent it like this:

local aspect = CreateFrame("Frame", nil, UIParent)
aspect:RegisterEvent("PLAYER_ENTERING_WORLD")
aspect:SetScript(
    "OnEvent",
    function(self, event)
        UIParent:SetScale(0.6)
        self:UnregisterAllEvents()
        print ("Your Resolution Scale has been changed to 0.6") 
    end
)

I realize that my method of indenting complex function arguments is not everyone's cup of tea, though; so, alternatively:

local aspect = CreateFrame("Frame", nil, UIParent)
aspect:RegisterEvent("PLAYER_ENTERING_WORLD")
aspect:SetScript("OnEvent", function(self, event)
        UIParent:SetScale(0.6)  -- you can change the scale here but you will break the entire add-on --
        self:UnregisterAllEvents()
        print ("Your Resolution Scale has been changed to 0.6") 
end)

Also, I changed aspect to self; I didn't see a reason to close on the aspect variable in that anonymous function when the frame reference is being passed into the function already.