ServerScriptService.ServerPlacement:10: bad argument #2 to '?' (string expected, got Object)

Hello! Im trying to make a sandbox style game (Like miners haven) and Im trying to subtract 1 from the number of items in a players inventory! The following script runs when the player places an item. However it always has the error ServerScriptService.ServerPlacement:10: bad argument #2 to '?' (string expected, got Object) What can I do to fix this? (The value im calling at the end is an IntValue)

local items = game:GetService("ReplicatedStorage").Items

game:GetService("ReplicatedStorage").ClientPlaced.OnServerEvent:Connect(function(player, itemName, location)
    local itemTemplate = items:FindFirstChild(itemName)

    if (itemTemplate) then
        local item = itemTemplate:clone()
        item.Parent = workspace.Base.ItemHolder
        item:SetPrimaryPartCFrame(location[1])
        game.Players[player].PlayerGui.PlayerScreen.Inventory.ImageButton.TextLabel[itemName].value = game.Players[player].PlayerGui.PlayerScreen.Inventory.ImageButton.TextLabel[itemName].value - 1
    end

end)

Also i tried it by doing it on the players end, however it subtracted 1 40-50 times!