Cant open stat Window again?

So I have a character stat window. To make it appear on the screen you need to click on the ImgButton. This ImgButton is located in the starterGUI. This button works fine.It has a notification script and a "AvailablePoints" text when you get points.

So the problem is i can open it and close it but i cant open it again. I get the error that takes me to the sample code

local Player = Game.Players.LocalPlayer

local GUI = Player.PlayerGui.HUD
GUI:WaitForChild("OpenStats")
GUI:WaitForChild("OpenArmor")

function OpenStats()
	if Player.PlayerGui:FindFirstChild("StatsGUI") == nil then
		Game.ReplicatedStorage.StatsGUI:Clone().Parent = Player.PlayerGui
	else print("GUI already open!")
	end
end

function OpenArmor()
	if Player.PlayerGui:FindFirstChild("ArmorGui") == nil then
		Game.ReplicatedStorage.ArmorGui:Clone().Parent = Player.PlayerGui
	else print("GUI already open!")
	end
end

GUI.OpenStats.MouseButton1Click:connect(OpenStats)
GUI.OpenArmor.MouseButton1Click:connect(OpenArmor)

exstra info

local script in the close txtButton

script.Parent.MouseButton1Click:Connect(function()
	script.Parent.Parent.Visible = false
end)

PointsNotification LocalScript

local Player = Game.Players.LocalPlayer

local Attributes = Player.attributes
local Leaderstat = Player.leaderstats
local Stats = Player.Stats

local Prop = Game.Workspace.GAME_PROPERTIES

local PGUI = Player.PlayerGui
PGUI:WaitForChild("HUD")
local GUI = PGUI.HUD
GUI:WaitForChild("OpenStats")
GUI.OpenStats:WaitForChild("AvailablePoints")

while true do
	if math.floor((Leaderstat.Lvl.Value / Prop.LevelsToGainPoints.Value) * Prop.PointGainIncrement.Value) + (Prop.StartingAttributes.Value * 4) + Prop.StartingAttributePoints.Value - (Attributes.Strength.Value + Attributes.Constitution.Value + Attributes.Intelligence.Value + Attributes.Dexterity.Value) > 0 then
		GUI.OpenStats.Style = "RobloxButtonDefault"
		GUI.OpenStats.AvailablePoints.Visible = true
	else GUI.OpenStats.Style = "RobloxButton"
		GUI.OpenStats.AvailablePoints.Visible = false
	end
	wait()
end
Anonymous