Keycode Is not a valid EnumItem?

My code is this:

--// Functions

UIS.InputBegan:Connect(function(Input) if Input.KeyCode == Enum.KeyCode.X then if Chatting == true then Exit = true Sounds.Click:Play() end end end)

UIS.InputBegan:Connect(function(Input) if Input.KeyCode == Enum.Keycode.Z then if Chatting == true then Exit = true Sounds.Click.Play() end end end)

UIS.InputBegan:Connect(function(Input) if Input.KeyCode == Enum.KeyCode.E then

    if Detected == true then
        local Lines = DetectedNPC:FindFirstChild("Lines")

And It keeps saying: Keycode Is not a valid EnumItem, I really need help.