Program: 672
Project: 672
Buggy source:
@Override public boolean step(){
  if (applyModuleThread != null) {
    if (!applyModuleThread.isAlive()) {
      if (oldEnvironment != null) {
        oldEnvironment.close();
      }
      return true;
    }
    return false;
  }
 else   if (joinStatus.getStatus() == JoinStatus.Status.COMPLETE) {
    Server server=networkSystem.getServer();
    ServerInfoMessage serverInfo=networkSystem.getServer().getInfo();
    if (serverInfo.getGameName().length() > 0) {
      gameManifest.setTitle(serverInfo.getGameName());
    }
 else {
      gameManifest.setTitle(server.getRemoteAddress());
    }
    for (    WorldInfo worldInfo : serverInfo.getWorldInfoList()) {
      gameManifest.addWorld(worldInfo);
    }
    Map<String,Short> blockMap=Maps.newHashMap();
    for (    Entry<Integer,String> entry : serverInfo.getBlockIds().entrySet()) {
      String name=entry.getValue();
      short id=entry.getKey().shortValue();
      Short oldId=blockMap.put(name,id);
      if (oldId != null && oldId != id) {
        logger.warn("String_Node_Str",oldId,name,id);
      }
    }
    Map<String,Short> biomeMap=Maps.newHashMap();
    for (    Entry<Short,String> entry : serverInfo.getBiomeIds().entrySet()) {
      String name=entry.getValue();
      short id=entry.getKey();
      Short oldId=biomeMap.put(name,id);
      if (oldId != null && oldId != id) {
        logger.warn("String_Node_Str",oldId,name,id);
      }
    }
    gameManifest.setRegisteredBlockFamilies(serverInfo.getRegisterBlockFamilyList());
    gameManifest.setBlockIdMap(blockMap);
    gameManifest.setBiomeIdMap(biomeMap);
    gameManifest.setTime(networkSystem.getServer().getInfo().getTime());
    ModuleManager moduleManager=context.get(ModuleManager.class);
    Set<Module> moduleSet=Sets.newLinkedHashSet();
    for (    NameVersion moduleInfo : networkSystem.getServer().getInfo().getModuleList()) {
      Module module=moduleManager.getRegistry().getModule(moduleInfo.getName(),moduleInfo.getVersion());
      if (module == null) {
        StateMainMenu mainMenu=new StateMainMenu("String_Node_Str" + moduleInfo);
        context.get(GameEngine.class).changeState(mainMenu);
        return false;
      }
 else {
        logger.info("String_Node_Str",moduleInfo.getName(),moduleInfo.getVersion());
        gameManifest.addModule(module.getId(),module.getVersion());
        moduleSet.add(module);
      }
    }
    oldEnvironment=moduleManager.getEnvironment();
    moduleManager.loadEnvironment(moduleSet,true);
    context.get(Game.class).load(gameManifest);
    EnvironmentSwitchHandler environmentSwitchHandler=context.get(EnvironmentSwitchHandler.class);
    applyModuleThread=new Thread(() -> environmentSwitchHandler.handleSwitchToGameEnvironment(context));
    applyModuleThread.start();
    return false;
  }
 else   if (joinStatus.getStatus() == JoinStatus.Status.FAILED) {
    StateMainMenu mainMenu=new StateMainMenu("String_Node_Str" + joinStatus.getErrorMessage());
    context.get(GameEngine.class).changeState(mainMenu);
  }
  return false;
}

Fixed version (ground truth):
@Override public boolean step(){
  if (applyModuleThread != null) {
    if (!applyModuleThread.isAlive()) {
      if (oldEnvironment != null) {
        oldEnvironment.close();
      }
      return true;
    }
    return false;
  }
 else   if (joinStatus.getStatus() == JoinStatus.Status.COMPLETE) {
    Server server=networkSystem.getServer();
    ServerInfoMessage serverInfo=networkSystem.getServer().getInfo();
    if (serverInfo.getGameName().length() > 0) {
      gameManifest.setTitle(serverInfo.getGameName());
    }
 else {
      gameManifest.setTitle(server.getRemoteAddress());
    }
    for (    WorldInfo worldInfo : serverInfo.getWorldInfoList()) {
      gameManifest.addWorld(worldInfo);
    }
    Map<String,Short> blockMap=Maps.newHashMap();
    for (    Entry<Integer,String> entry : serverInfo.getBlockIds().entrySet()) {
      String name=entry.getValue();
      short id=entry.getKey().shortValue();
      Short oldId=blockMap.put(name,id);
      if (oldId != null && oldId != id) {
        logger.warn("String_Node_Str",oldId,name,id);
      }
    }
    Map<String,Short> biomeMap=Maps.newHashMap();
    for (    Entry<Short,String> entry : serverInfo.getBiomeIds().entrySet()) {
      String name=entry.getValue();
      short id=entry.getKey();
      Short oldId=biomeMap.put(name,id);
      if (oldId != null && oldId != id) {
        logger.warn("String_Node_Str",oldId,name,id);
      }
    }
    gameManifest.setRegisteredBlockFamilies(serverInfo.getRegisterBlockFamilyList());
    gameManifest.setBlockIdMap(blockMap);
    gameManifest.setBiomeIdMap(biomeMap);
    gameManifest.setTime(networkSystem.getServer().getInfo().getTime());
    ModuleManager moduleManager=context.get(ModuleManager.class);
    Set<Module> moduleSet=Sets.newLinkedHashSet();
    for (    NameVersion moduleInfo : networkSystem.getServer().getInfo().getModuleList()) {
      Module module=moduleManager.getRegistry().getModule(moduleInfo.getName(),moduleInfo.getVersion());
      if (module == null) {
        StateMainMenu mainMenu=new StateMainMenu("String_Node_Str" + moduleInfo);
        context.get(GameEngine.class).changeState(mainMenu);
        return false;
      }
 else {
        logger.info("String_Node_Str",moduleInfo.getName(),moduleInfo.getVersion());
        gameManifest.addModule(module.getId(),module.getVersion());
        moduleSet.add(module);
      }
    }
    oldEnvironment=moduleManager.getEnvironment();
    moduleManager.loadEnvironment(moduleSet,true);
    context.get(Game.class).load(gameManifest);
    EnvironmentSwitchHandler environmentSwitchHandler=context.get(EnvironmentSwitchHandler.class);
    applyModuleThread=new Thread(() -> environmentSwitchHandler.handleSwitchToGameEnvironment(context));
    applyModuleThread.start();
    return false;
  }
 else   if (joinStatus.getStatus() == JoinStatus.Status.FAILED) {
    StateMainMenu mainMenu=new StateMainMenu("String_Node_Str" + joinStatus.getErrorMessage());
    context.get(GameEngine.class).changeState(mainMenu);
    networkSystem.shutdown();
  }
  return false;
}