Program: 32578
Project: 32578
Buggy source:
@Override public void execute(CommandSender sender,String[] args){
  MessagesConfig messages=Messages.getInstance();
  if (args.length < 1) {
    sender.sendMessage(messages.generalNoTagGiven);
    return;
  }
  Guild guild=GuildUtils.byTag(args[0]);
  if (guild == null) {
    sender.sendMessage(messages.generalNoGuildFound);
    return;
  }
  if (args.length < 2) {
    sender.sendMessage(messages.generalNoNickGiven);
    return;
  }
  if (!UserUtils.playedBefore(args[1])) {
    sender.sendMessage(messages.generalNotPlayedBefore);
    return;
  }
  User user=User.get(args[1]);
  Player player=user.getPlayer();
  if (!guild.getMembers().contains(user)) {
    sender.sendMessage(messages.adminUserNotMemberOf);
    return;
  }
  User admin=(sender instanceof Player) ? User.get(sender.getName()) : null;
  if (!SimpleEventHandler.handle(new GuildMemberDeputyEvent(admin == null ? EventCause.CONSOLE : EventCause.ADMIN,admin,guild,user))) {
    return;
  }
  MessageTranslator translator=new MessageTranslator().register("String_Node_Str",user.getName());
  if (user.isDeputy()) {
    guild.setDeputy(null);
    sender.sendMessage(messages.deputyRemove);
    if (player != null) {
      player.sendMessage(messages.deputyMember);
    }
    String message=translator.translate(messages.deputyNoLongerMembers);
    for (    User member : guild.getOnlineMembers()) {
      member.getPlayer().sendMessage(message);
    }
    return;
  }
  guild.setDeputy(user);
  sender.sendMessage(messages.deputySet);
  if (player != null) {
    player.sendMessage(messages.deputyOwner);
  }
  String message=translator.translate(messages.deputyMembers);
  for (  User member : guild.getOnlineMembers()) {
    member.getPlayer().sendMessage(message);
  }
}

Fixed version (ground truth):
@Override public void execute(CommandSender sender,String[] args){
  MessagesConfig messages=Messages.getInstance();
  if (args.length < 1) {
    sender.sendMessage(messages.generalNoTagGiven);
    return;
  }
  Guild guild=GuildUtils.getByTag(args[0]);
  if (guild == null) {
    sender.sendMessage(messages.generalNoGuildFound);
    return;
  }
  if (args.length < 2) {
    sender.sendMessage(messages.generalNoNickGiven);
    return;
  }
  if (!UserUtils.playedBefore(args[1])) {
    sender.sendMessage(messages.generalNotPlayedBefore);
    return;
  }
  User user=User.get(args[1]);
  Player player=user.getPlayer();
  if (!guild.getMembers().contains(user)) {
    sender.sendMessage(messages.adminUserNotMemberOf);
    return;
  }
  User admin=(sender instanceof Player) ? User.get(sender.getName()) : null;
  if (!SimpleEventHandler.handle(new GuildMemberDeputyEvent(admin == null ? EventCause.CONSOLE : EventCause.ADMIN,admin,guild,user))) {
    return;
  }
  MessageTranslator translator=new MessageTranslator().register("String_Node_Str",user.getName());
  if (user.isDeputy()) {
    guild.setDeputy(null);
    sender.sendMessage(messages.deputyRemove);
    if (player != null) {
      player.sendMessage(messages.deputyMember);
    }
    String message=translator.translate(messages.deputyNoLongerMembers);
    for (    User member : guild.getOnlineMembers()) {
      member.getPlayer().sendMessage(message);
    }
    return;
  }
  guild.setDeputy(user);
  sender.sendMessage(messages.deputySet);
  if (player != null) {
    player.sendMessage(messages.deputyOwner);
  }
  String message=translator.translate(messages.deputyMembers);
  for (  User member : guild.getOnlineMembers()) {
    member.getPlayer().sendMessage(message);
  }
}