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)