Script Detects StringValue as a Table. Why and how do i fix it?

I have a AutoShutdownScript on my game that was not made by me and it has an error. A value is detected as a table, not a string value as it is supposed to be.

if placeId == 0 then script:Destroy() end -- No proper info.
local market = game:WaitForChild("MarketplaceService")
local serverVersion = Instance.new("StringValue",game) --This is the StringValue that is detected as a table

serverVersion.Value = market:GetProductInfo(placeId) --This line is where it errors
serverVersion.Name = "SERVER_VERSION"

while true do --Extra code in the script if you want to see it
	game:GetService("RunService").Stepped:wait()
	local currentVersion = market:GetProductInfo(placeId)
	if currentVersion ~= serverVersion.Value then
		if manualShutDown ~= true then
			local m = Instance.new("Message",workspace)
			m.Text = "This game has been updated! Shutting down server..."
			wait(1)
			Instance.new("ManualSurfaceJointInstance",workspace)
		else
			local f,s = string.find(currentVersion,"autoshutdown:go")
			if f ~= nil and s ~= nil then
				local m = Instance.new("Message",workspace)
				m.Text = "This game has been updated! Shutting down server..."
				wait(1)
				Instance.new("ManualSurfaceJointInstance",workspace)
			end
		end
	end
end																															

Please Help