Help with saving and Loading Number Values?

game.Players.PlayerAdded:connect(function(player)
    local stats = Instance.new("IntValue", player)
    stats.Name = "leaderstats"

    local level = Instance.new("IntValue", stats)
    level.Name = "Level"
    level.Value = 1

    local new = Instance.new("IntValue", player)
    new.Name = "New"
    new.Value = 0

    local complete = Instance.new("IntValue", player)
    complete.Name = "Complete"
    complete.Value = 0


    if not stats then 
        return
    end

    if not complete then 
        return 
    end

    player:SaveNumber("Complete", complete.Value)
end)

game.Players.PlayerRemoving:connect(function(player)
    player:WaitForDataReady()

    local stats = player:FindFirstChild("leaderstats")
    if not stats then 
        return 
    end

    local complete = player:FindFirstChild("Complete")
    if not complete then 
        return 
    end

    player:SaveNumber("Complete", complete.Value)
end)

I want it to save the players Complete stats when they leave and laod when they join. I enabled all the data store stuff to studio, but it keeps saying Data is not ready for DataStore, or something along those lines. Please help.