"ScreenGui is not a valid member of PlayerGui." It definitely is. ???

I am making a sandbox game in roblox where players can make their own obby. I have come across an EXTREMELY outrageous and frustrating glitch in my game that in the developer console, it says "ScreenGui is not a valid member of PlayerGui," even though i can still see all the other descendants of that same screengui on my screen. It works in studio but not in Roblox player. This is definitely the most frustrating and confusing glitch i've ever came across. When I use WaitForChild("ScreenGui") it says "Infinite Yield Possible" and never runs the script.

Edit:

Here's the scripts im using:

In a model (Regular Script):

part = script.Parent

function configure(player)
	if player.Team.Name == part.Parent.Parent.Name then
		player.PlayerGui.ScreenGui.EditObject.Object.Value = part
	end
end

part.ClickDetector.MouseClick:connect(configure)

in a TextLabel in a Descendent of ScreenGUI (LocalScript):

while true do
function updateText()
	if script.Parent.Parent.Object.Value then
		script.Parent.Text = script.Parent.Parent.Object.Value.Name
	end
end

wait()

updateText()
end