Will check if player data IS fully loaded before saving when the player left the server.
If the access from your server to a database is somewhat slow or limited you should update ASAP to avoid data loss.
Added Messages.Loading-Data, if player's data still loading when using a Placeholder or stats command.
Just a heads up, everything was tested and no data loss registered, but I'd recommend you to backup your database (mysql or players.db file) if possible.