How do I fix "DataStore request was added to queue" ?

I keep getting this error that says "Datastore request was added to queue. If request queue fills, further requests will be dropped. Try sending fewer requests." Every time I stop the game. I don't know what I did wrong. Can someone help me? Thanks.

local player = game:GetService("Players")
local dataStoreService = game:GetService("DataStoreService")
local saveDataStore = dataStoreService:GetDataStore("ObbyDataSave1")

local function savePlrData(plr)

    local success,err = pcall(function()

        local saveData = {}

        for _,stat in pairs(plr.leaderstats:GetChildren())do

            saveData[stat.Name] = stat.Value

        end

        saveDataStore:SetAsync(plr.UserId,saveData)

    end)

    if not success then return err end

end

player.PlayerAdded:connect(function(plr)

    local stats = Instance.new("Folder")
    stats.Name = "leaderstats"
    stats.Parent = plr

    local stage = Instance.new("IntValue")
    stage.Name = "Stage"
    stage.Parent = stats

    local data = saveDataStore:GetAsync(plr.UserId)

    if data then

        print(data.Stage)

        for _,stat in pairs(stats:GetChildren()) do

            stat.Value = data[stat.Name]

    end

else

        print(plr.Name .. " has no data")

    end

    plr.CharacterAdded:connect(function(char)

        local humanoid,hrp = char:WaitForChild("Humanoid"),char:WaitForChild("HumanoidRootPart")

        wait()

        if humanoid and hrp then

            if stage.Value ~= 0 then

                local part = workspace.ObbyStages:FindFirstChild(stage.Value)
                hrp.CFrame = part.CFrame + Vector3.new(0,1,0)

            end

        end

    end)

end)

player.PlayerRemoving:connect(function(plr)

    local err = savePlrData(plr)

    if err then print(err) end

end)

game:BindToClose(function()

    for _,plr in pairs(player:GetPlayers()) do

        local err = savePlrData(plr)

        if err then print(err) end

    end

    wait(2)

end)