Getting a "attempt to index a nil value" error in my DataStore2?

The output tells me there's an error line 54 of my script, but I don't quite understand why?

local DataStore2 = require(game.ServerScriptService:WaitForChild("DataModule")) --Gets DataStore Module
local MainKey = "MainKey" -- The Key
DataStore2.Combine(MainKey,"Stats","Achievment")

--DataTable

local function SetDataTable()-- Setting Variables In A Table
    local UserData = {
        Stats = {
            ["Kills"] = 0,
            ["Deaths,"] = 0,
            ["XP"] = 0,
            ["Level"] = 1,
            ["Coins"] = 0,

        },


    }
end


game.Players.PlayerAdded:Connect(function(plr) -- Does Function When Player Joins
    local UserData = DataStore2(MainKey,plr) --Gets Table


    local leaderstats = Instance.new("Folder") ---Leaderstats!--
    leaderstats.Name = "leaderstats"

    local kills = Instance.new("IntValue")
    kills.Name = "Kills"    

    local deaths = Instance.new("IntValue")
    deaths.Name = "Deaths"

    local xp = Instance.new("IntValue")
    xp.Name = "Xp"

    local xpn = Instance.new("IntValue")
    xpn.Name = "Xpn"

    local level = Instance.new("IntValue")
    level.Name = "Level"

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

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

    local StatsData = DataStore2("Stats",plr)

    local function UpdateStats(updatedValue) --Updates Data
        kills.Value = StatsData:Get(updatedValue).kills
        deaths.Value = StatsData:Get(updatedValue).deaths
        xp.Value = StatsData:Get(updatedValue).xp
        xpn.Value = StatsData:Get(updatedValue).xpn
        level.Value = StatsData:Get(updatedValue).level
        coins.Value = StatsData:Get(updatedValue).coins
        gems.Value = StatsData:Get(updatedValue).gems       
    end



    UpdateStats(UserData.Stats) -- updates data and calls the function

    StatsData:OnUpdate(UpdateStats) -- calls func on update

    --Parenting Properties
    leaderstats.Parent = plr
    kills.Parent = leaderstats
    deaths.Parent = leaderstats
    xp.Parent = leaderstats
    level.Parent = leaderstats
    coins.Parent = leaderstats
    gems.Parent = leaderstats

    --Giving Stats

    while true do
        wait(200)
        local KeyData = DataStore2(MainKey)
        KeyData:Save()
    end

    local function LevelUp()
        print("test")
    end
end)