Why won't this script work?

I've asked this before, got one answer, tried it and it worked in STUDIO mode. Not in PLAY mode on the website. I looked through it millions of times and its all correct. What is going on? This is not a local script.

wait(.5)
local gui =  script.Parent.Parent.Parent.night_GUI:Clone()

function Equip()
	gui.Parent = game.Players.LocalPlayer.PlayerGui
end
script.Parent.MouseClick:connect(Equip)