Datastore not saving dating and not giving an error?

This script is a datastore for leaderstats. Obviously, its supposed to save, but I doesn't. It worked at first but I changed some things in in and now it doesn't work, whats wrong?

Code:

local dataStoreService = game:GetService("DataStoreService")
local myDataStore = dataStoreService:GetDataStore("MainDataStore")

local playersLeft = 0

-- Load leaderstats
game.Players.PlayerAdded:Connect(function(player)

    playersLeft = playersLeft + 1

    -- Leaderstats 

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

    -- Coins
    local coins = Instance.new("IntValue")
    coins.Name = "Coins"
    coins.Parent = leaderstats

    -- Gems
    local gems = Instance.new("IntValue")
    gems.Name = "Gems"
    gems.Parent = leaderstats

    -- Levels
    local levels = Instance.new("IntValue")
    levels.Name = "Level"
    levels.Parent = leaderstats

    -- Load data

    local PlayerUserId = player.UserId -- Player key to store data

    local player_data

    -- Data to load in
    local dataTable1 = {
        Coins = player.leaderstats.Coins.Value;
        Gems = player.leaderstats.Gems.Value;
        Levels = player.leaderstats.Level.Value;
    }

    local success, errorMessage = pcall(function()
        player_data = myDataStore:GetAsync(PlayerUserId)
    end)

    -- Load data

    if success then
        coins.Value = dataTable1.Coins
        gems.Value = dataTable1.Gems
        levels.Value = dataTable1.Levels
    end
end)

local bindableEvent = Instance.new("BindableEvent")

-- Player leaves
game.Players.PlayerRemoving:Connect(function(player)

    local playerUserId = player.UserId -- Player key

    -- Data table
    local dataTable2 = {
        Coins = player.leaderstats.Coins.Value;
        Gems = player.leaderstats.Gems.Value;
        Levels = player.leaderstats.Level.Value;
    }

    local success, errorMessage = pcall(function()
        myDataStore:SetAsync(playerUserId, dataTable2)

        playersLeft = playersLeft - 1

        bindableEvent:Fire()
    end)

    if success then
        print("Data saved")
    else
        print("Error saving data")
        warn(errorMessage)
    end
end)

if playersLeft > 0 then
    bindableEvent.Event:Wait()
end