Doesn't work in normal servers but works fine in studio?

i need help on this, i made a inventory but just works on studio am starting to scripting and i spent alot on this so any help?

player = game.Players.LocalPlayer

game.StarterGui:SetCoreGuiEnabled('Backpack',false)

--
local Enabled = false


function UpdateInventory()
	if Enabled == false then
		Enabled = true
		script.Parent.Frame.Visible = true
		script.Parent.Frame.CanvasSize = UDim2.new(0,0,0,20*#player.Backpack:children())
		script.Parent.Frame:ClearAllChildren()
		for i,v in pairs(player.Backpack:GetChildren()) do
			Obj1 = Instance.new('TextButton',script.Parent.Frame)
			Obj1.Size = UDim2.new(1,-12,0,20)
			Obj1.Position = UDim2.new(0,0,0,20*i-20)
			Obj1.BackgroundTransparency = 1
			Obj1.FontSize = 'Size24'
			Obj1.Text = v.Name
			Obj1.Font = 'SourceSansBold'
			Obj1.TextColor3 = Color3.new(255,255,255)
			Obj1.TextXAlignment = 'Left'
			Obj1.MouseButton1Down:connect(function()
				player.Character.Humanoid:UnequipTools(v)
				player.Character.Humanoid:EquipTool(v)
			end)
		end
	else
		Enabled = false
		script.Parent.Frame.Visible = false
	end
end

script.Parent.InvenButton.MouseButton1Down:connect(function()
	UpdateInventory()
end)

player.Backpack.Changed:connect(function()
	if Enabled == false then Enabled = true UpdateInventory() end
	if Enabled == true then Enabled = false UpdateInventory() end
end)