src/de/steamwar/lobby/command/ModifyCommand.java

@@ -55,6 +55,7 @@ public class ModifyCommand extends SWCommand implements Listener {
 
         if(modifying(player)) {
             modifying.remove(player);
+            LobbySystem.getEntityServer(true).removePlayer(player);
             player.setGameMode(GameMode.ADVENTURE);
             player.setOp(false);
             PlayerSpawn.giveItems(player);