Why doesn't this method straight from the wiki work?

For several days I have been wondering why this method of saving player data doesn't work. Can anyone try this method out, and vouch that it doesn't work?

What would you need to do to test:

1) Create a ModuleScript

2) Place the ModuleScript inside the ServerStorage

3) Paste this code unedited, directly from the wiki inside the ModuleScript:

-- Set up table to return to any script that requires this module script
local PlayerStatManager = {}

local DataStoreService = game:GetService("DataStoreService")
local playerData = DataStoreService:GetDataStore("PlayerData")

-- Table to hold player information for the current session
local sessionData = {}

local AUTOSAVE_INTERVAL = 60

-- Function that other scripts can call to change a player's stats
function PlayerStatManager:ChangeStat(player, statName, value)
    assert(typeof(sessionData[playerUserId][statName]) == typeof(value), "ChangeStat error: types do not match")
    local playerUserId = "Player_" .. player.UserId
    if typeof(sessionData[playerUserId][statName]) == "number" then
        sessionData[playerUserId][statName] = sessionData[playerUserId][statName] + value
    else
        sessionData[playerUserId][statName] = value
    end
end

-- Function to add player to the 'sessionData' table
local function setupPlayerData(player)
    local playerUserId = "Player_" .. player.UserId
    local data
    local success, err = pcall(function()
        playerData:UpdateAsync(playerUserId, function(playerData)
            data = playerData
        end)
    end)

    if success then
        if data then
            -- Data exists for this player
            sessionData[playerUserId] = data
        else
            -- Data store is working, but no current data for this player
            sessionData[playerUserId] = {Money=0, Experience=0}
        end
    else
        warn("Cannot set up data for player!")
    end
end

-- Function to save player's data
local function savePlayerData(playerUserId)
    if sessionData[playerUserId] then
        local success, err = pcall(function()
            playerData:SetAsync(playerUserId, sessionData[playerUserId])
        end)
        if not success then
            warn("Cannot save data for player!")
        end
    end
end

-- Function to save player data on exit
local function saveOnExit(player)
    local playerUserId = "Player_" .. player.UserId
    savePlayerData(playerUserId)
end

-- Function to periodically save player data
local function autoSave()
    while wait(AUTOSAVE_INTERVAL) do
        for playerUserId, data in pairs(sessionData) do
            savePlayerData(playerUserId)
        end
    end
end

-- Start running 'autoSave()' function in the background
spawn(autoSave)

-- Connect 'setupPlayerData()' function to 'PlayerAdded' event
game.Players.PlayerAdded:Connect(setupPlayerData)

-- Connect 'saveOnExit()' function to 'PlayerRemoving' event
game.Players.PlayerRemoving:Connect(saveOnExit)

return PlayerStatManager

4) Create a Script and place it inside of the ServerScriptService

5) Copy this code into the script:

local serverstorage = game:GetService("ServerStorage")
local module = require(serverstorage.ModuleScript)

game:GetService("Players").PlayerAdded:Connect(function(player)
    local stats = Instance.new("Folder")
    stats.Name = 'leaderstats'
    stats.Parent = player

    local money = Instance.new("NumberValue")
    money.Name = 'Money'
    money.Parent = stats

    local experience = Instance.new("NumberValue")
    experience.Name = 'Experience'
    experience.Parent = stats

    module:ChangeStat(player, 'Money', 5)
end)

6) Check 'Enable Studio Access to API Services' located in the Configure this game settings.

7) Report back your findings.

Any help would be appreciated, thanks.