MySQLPlayerDataSync

To login two server at the same time with two client one account occured item duplication. I fixed by manage information if the player is online or not. So, If same person logged in another server using same sql database, he can't join the server. I strongly recommend you updating immediately. You don't need to reset your database. YOU ONLY DO THE FOLLOWING COMMAND IN MYSQL CONSOLE. use minecraft; alter table player add online tinyint(1) default 0 after name;