attempt to index nil with 'Item' Help?

I have a inventory gui that I am making so you can move to "Sort" your inventory. It will not work, It always errors. Here is the script (Normal script inside text button):

local MovingInventory = script.Parent.Parent.Parent.Parent.Parent.MovingInventory
local SlotMoving = script.Parent.Parent.Parent.Parent.Parent.MovingInventory

script.Parent.MouseButton1Click:Connect(function()
    if MovingInventory.Value == false then
        MovingInventory.Value = true
        SlotMoving.Value = script.Parent.Name
    elseif MovingInventory.Value == true then
        MovingInventory.Value = false
        game.ReplicatedStorage.Values:WaitForChild("Item").Value = script.Parent.Parent:FindFirstChild(SlotMoving.Value).Item.Value
        game.ReplicatedStorage.Values:WaitForChild("Amount").Value = script.Parent.Parent:FindFirstChild(SlotMoving.Value).Amount.Value
        script.Parent.Item.Value = script.Parent.Parent:FindFirstChild(SlotMoving.Value).Item.Value
        script.Parent.Amount.Value = script.Parent.Parent:FindFirstChild(SlotMoving.Value).Amount.Value
        script.Parent.Parent:FindFirstChild(SlotMoving.Value).Item.Value = game.ReplicatedStorage.Values.Item.Value
        script.Parent.Parent:FindFirstChild(SlotMoving.Value).Amount.Value = game.ReplicatedStorage.Values.Amount.Value
    end
end)

Thoughts, thanks!