[Lesteryoung]

local CoordText = WorldMapFrame.BorderFrame.TitleText
 
local totalElapsed = 0
WorldMapDetailFrame:HookScript('OnUpdate', function(self, elapsed)
    if(totalElapsed > 0.1) then
        if(WorldMapScrollFrame:IsMouseOver()) then
            local scale = self:GetEffectiveScale()
            local centerX, centerY = self:GetCenter()
            local width, height = self:GetSize()
            local x, y = GetCursorPosition()
 
            x = ((x / scale) - (centerX - (width / 2))) / width
            y = (centerY + (height / 2) - (y / scale)) / height
 
            CoordText:SetFormattedText('%.0f , %.0f', x * 100, y * 100)
            CoordText:SetTextColor(0, 1, 0)
        else
            local x, y = GetPlayerMapPosition('player')
            CoordText:SetFormattedText('%.0f , %.0f', x * 100, y * 100)
            CoordText:SetTextColor(1, 1, 0)
        end
 
        totalElapsed = 0
    else
        totalElapsed = totalElapsed + elapsed
    end
end)

Is throwing this error, repeatedly.

25x Tweaks\Coordinates.lua:19: attempt to perform arithmetic on local 'x' (a nil value)
Tweaks\Coordinates.lua:19: in function <Tweaks\Coordinates.lua:4>

Locals:
self = WorldMapDetailFrame {
 0 = <userdata>
}
elapsed = 0.015000000596046
x = nil
y = nil
(*temporary) = <function> defined =[C]:-1
(*temporary) = WorldMapFrameTitleText {
 0 = <userdata>
}
(*temporary) = "%.0f , %.0f"
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to perform arithmetic on local 'x' (a nil value)"
totalElapsed = 0.11200000345707
CoordText = WorldMapFrameTitleText {
 0 = <userdata>

Any ideas as to why? It seems to happen inside instances.

Thanks.