[Mischback]

Originally Posted by neverg i = Auras.visibleAuras local i=i+i Returns this error: Interface\AddOns\oUF_lumen\oUF_lumen.lua:630: attempt to perform arithmetic on local 'i' (a nil value)

Without wanting to say anything against p3lim or Saiket, 'cause they made valid points, let me just point out, that your code makes no sense...

You set i to some value (and yes, it should be set and an arithmetic) and then you declare i as local.
I'm not quite sure, what Lua and WoW will make out of this, but you should try something like this:

local i = Auras.visibleAuras
i=i+i

I'm can't imagine what this is about, but from the pure source-code-view it should work. Of course, local i = Auras.visibleAuras * 2 will provide the exact same result.