Why is this global function only working in solo mode?

I have a global function that I am using here to make a GUI visible. The problem is that despite the fact that there is another global function preceding it, when I attempt to play it(works in solo) it responds in the console that "attempted to call field round but was nil." If it matters, the global function is in a GUI. and this isn't a local script.

function begin()-- function calling Global Functions
wait(5)
_G.blue() -- This one appears to work
wait()
_G.round() -- Comes up as nil
end

_G["round"] = function()-- This is the part that names the "round function." There is more to this function, but I don't think that stuff should affect it.

So is there a reason why this is happening and why does it work in solo only? Hope you can help. Thanks.