Why bind to close function in my datastore script gives an error?

So i improved my datastore script to make it work but output said: ServerScriptService.Events.ComData:22: attempt to call a nil value Script:

local ds = game:GetService("DataStoreService")
	local bool = ds:GetDataStore("ComSaving")
game.Players.PlayerAdded:Connect(function(plr)
	print("Player Joining...")
		    local boolValue = plr:WaitForChild("PlayerGui"):WaitForChild("QuestGui").CompletedData
		    boolValue.Value = bool:GetAsync(plr.UserId) or false
		end)
	 
game.Players.PlayerRemoving:Connect(function(plr)
	print("Player Leaving...")
	--local success, err = pcall(function()
		bool:SetAsync(plr.UserId, plr.PlayerGui.QuestGui.CompletedData.Value)
		end)
--end)

game:BindToClose(function()
	print("Bind is loading...")
	for i, v in pairs(game.Players:GetPlayers()) do
		local data = {
			["QCA"] = v.PlayerGui.QuestGui.CompletedData.Value,
		}
		data:GetAsync(v.UserId, data)
	end
end)