weld not working? (characteradded weld)

the full script is:

wait(0.5)

Ui = script.parent
game.Players.PlayerAdded:Connect(function(Player)
    Player.CharacterAdded:Connect(function(Character)
        local Torso = Character.UpperTorso
        local weld = Instance.new('Weld', Ui)
        weld.Parent = Ui
        weld.Part0 = Ui
        weld.Part1 = Torso
        weld.C0 = CFrame.new(0,2,0)
        weld.C1 = CFrame.new(0,0,1)
    end)
end)

(this script is inside a brick inside workspace)

what i am trying to do is: the player joins the game the a part just welds the the uppertorso(R15)

if you need any more information just comment ill add it as fast as i can