PlayerGui only works for me, not others!?

Every time i use a PlayerGui (brick onTouch) a GUI pops up for me and thats great, but then when a person touches the same button after me it doesn't work. Why is that? Please don't thumbs down, i just need to know

debounce = false

script.Parent.Touched:connect(function(hit)
    if debounce == false then
        debounce = true
local   humanoid = hit.Parent:FindFirstChild("Humanoid")
    if humanoid then
        local player = game.Players:GetPlayerFromCharacter(hit.Parent)
        player.PlayerGui.Intro.Window.Text.Visible = true
        player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,150))
        player.PlayerGui.Intro.Window.Text.Text = "Remember what i said? Red bricks are a no no. Try to avoid them as much as possible! (Hint: They kill you) ~NonSpace"
        -- first time learning Tweening!
                wait(10)
        player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,400))
        wait(1)
        player.PlayerGui.Intro.Window.Text.Visible = false

        debounce = false
        end
    end
end)

Your problem was the debounce, the other user would have been able to step on the part 11 seconds after you, because after that time, the debounce would have been set to false. This is because the script is not local, the debounce is set for every single user in the game. To fix this, I've made it add a 'Model' named 'Debounce' to the Player's Humanoid so that multiple people will be able to step on it at the same time.

script.Parent.Touched:conenct(function(Hit)
	local Humanoid=Hit.Parent:FindFirstChild("Humanoid")
	if Humanoid then
		if Humanoid:FindFirstChild("Debounce") then return end
		local Debounce=Instance.new("Model",Humanoid)
		Debounce.Name="Debounce"
		local Player=game.Players:FindFirstChild(Hit.Parent.Name)
		Player.PlayerGui.Intro.Window.Text.Visible=true
		Player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,150))
		Player.PlayerGui.Intro.Window.Text.Text="Remember what I said? Red bricks are a no-no. Try to avoid them as much as possible! (Hint: They kill you) ~NonSpace"
		wait(10)
		Player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,400))
		wait(1)
		Player.PlayerGui.Intro.Window.Text.Visible=false
		Debounce:destroy()
	end
end)

I edited the coding a bit, you had 99% of it correct.

This should correctly work now. Make sure the GUI is in your StarterGui!

script.Parent.Touched:connect(function(hit)
local  humanoid = hit.Parent:FindFirstChild("Humanoid")
    if humanoid then
        local player = game.Players:GetPlayerFromCharacter(hit.Parent)
        player.PlayerGui.Intro.Window.Visible = true
        player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,150))
        player.PlayerGui.Intro.Window.Text.Text = "Remember what i said? Red bricks are a no no. Try to avoid them as much as possible! (Hint: They kill you) ~NonSpace"
         wait(3)
        player.PlayerGui.Intro.Window:TweenPosition(UDim2.new(0,0,0.5,400))
        wait(1)
        player.PlayerGui.Intro.Window.Visible = false
    end
end)

Please don't post duplicate questions.

You could simply use a table to check who is actively receiving this message.

I also cleaned up the code by remove the unneeded humanoid check and using the variable window.

local peoples = {}

script.Parent.Touched:connect(function(hit)
	local player = game.Players:GetPlayerFromCharacter(hit.Parent)
	if player and not peoples[player.Name] then
		peoples[player.Name] = true
		local window = player.PlayerGui.Intro.Window
		window.Text.Visible = true
		window:TweenPosition(UDim2.new(0,0,0.5,150))
		window.Text.Text = "Remember what i said? Red bricks are a no no. Try to avoid them as much as possible! (Hint: They kill you) ~NonSpace"
		wait(10)
		window:TweenPosition(UDim2.new(0,0,0.5,400))
		wait(1)
		window.Text.Visible = false
		peoples[player.Name] = false --You could also remove this line if you want this to only show up once no matter how many times they touch the brick.
	end
end)