"When they leave the game their data gets saved and when they get an error it will say reload game. do not kick the person"

-- data store script (ServerScriptService) 
local DataStoreService = game:GetService("DataStoreService")
local Players = game:GetService("Players")
local dataStore = DataStoreService:GetDataStore("PlayerData")

local function saveData(player)
    local success, err = pcall(function()
        local data = {
            Coins = player.leaderstats.Coins.Value,
            Bag = player.leaderstats.Bag.Value
        }
        dataStore:SetAsync(player.UserId, data)
    end)

if not success then
        player:Kick("An error occurred while saving your data. Please reload the game.")
    end
end

local function loadData(player)
    local success, err = pcall(function()
        local data = dataStore:GetAsync(player.UserId)
        if data then
            player.leaderstats.Coins.Value = data.Coins
            player.leaderstats.Bag.Value = data.Bag
        end
    end)

if not success then
        player:Kick("An error occurred while loading your data. Please reload the game.")
    end
end

Players.PlayerAdded:Connect(function(player)
    player.CharacterAdded:Wait()
    loadData(player)
end)

Players.PlayerRemoving:Connect(function(player)
    saveData(player)
end)