When I try to remove a GUI it doesn't work and no error message is given, why?

I am trying to make a GUI disappear when I click it but nothing happens. I put print("") to see if it works and I get the first print and not the second one. The StarterGUI is disabled but not the PlayerGUI one. Why?

ImageGui = script.Parent
OnorOff = game.StarterGui.ScreenGui

ImageGui.MouseButton1Click:Connect(function(player)
	print("This.Works")  --Prints to see if the code ran through here
	OnorOff.Enabled = false
	game.Players:WaitForChild("player.Name").PlayerGui.ScreenGui.Enabled = false
	print("This.Also.Works") --Prints to see if the code ran through here
end)

First you need to get the player's version of the GUI. This basically means that whatever was in the StarterGui is cloned into the player's PlayerGui, so in your script your not indexing the player's version of the GUI.

local imagegui = script.Parent
local onoroff = game:GetService("Players").LocalPlayer.PlayerGui:FindFirstChild("ScreenGui")

imagegui.MouseButton1Click:Connect(function() --the 'player' parameter isn't needed.
	onoroff.Enabled = not onoroff.Enabled --not reverses something, so if the player clicks the button once, it disables the gui. when the player clicks it again, it enables gui. you can change this to false if you want to though.
end)

Hopefully this made sense to you, and if it did please accept my answer!

On line 7, I don't think you are supposed to put quotation marks around player.Name. So it should look like this:

ImageGui = script.Parent
OnorOff = game.StarterGui.ScreenGui

ImageGui.MouseButton1Click:Connect(function(player)
    print("This.Works")  --Prints to see if the code ran through here
    OnorOff.Enabled = false
    game.Players:WaitForChild(player.Name).PlayerGui.ScreenGui.Enabled = false
    print("This.Also.Works") --Prints to see if the code ran through here
end)