Program: 133986
Project: 133986
Buggy source:
@Override public void execute(CommandSender sender,List<String> args){
  if (!hasPermission(sender) || !correctLength(sender,args.size(),1,2)) {
    return;
  }
  Player player=Bukkit.getPlayer(args.get(0));
  if (player == null) {
    sender.sendMessage(ChatColor.RED + "String_Node_Str");
    return;
  }
  BendingPlayer bPlayer=GeneralMethods.getBendingPlayer(player.getName());
  if (bPlayer == null) {
    GeneralMethods.createBendingPlayer(player.getUniqueId(),player.getName());
    bPlayer=GeneralMethods.getBendingPlayer(player.getName());
  }
  if (args.size() == 2) {
    if (Element.getType(args.get(1)) != null) {
      bPlayer.getElements().remove(Element.getType(args.get(1)));
      GeneralMethods.removeUnusableAbilities(player.getName());
      if (Element.getType(args.get(1)) == Element.Chi) {
        sender.sendMessage(ChatColor.GREEN + "String_Node_Str" + args.get(1).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ player.getName());
        player.sendMessage(ChatColor.GREEN + "String_Node_Str" + args.get(1).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ sender.getName());
      }
 else {
        sender.sendMessage(ChatColor.GREEN + "String_Node_Str" + args.get(1).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ player.getName());
        player.sendMessage(ChatColor.GREEN + "String_Node_Str" + args.get(1).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ sender.getName());
      }
      Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,Element.getType(args.get(1)),Result.REMOVE));
      return;
    }
  }
  bPlayer.getElements().clear();
  GeneralMethods.saveElements(bPlayer);
  GeneralMethods.removeUnusableAbilities(player.getName());
  sender.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.DARK_AQUA+ player.getName());
  player.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.DARK_AQUA+ sender.getName());
  Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,null,Result.REMOVE));
}

Fixed version (ground truth):
@Override public void execute(CommandSender sender,List<String> args){
  if (!hasPermission(sender) || !correctLength(sender,args.size(),1,2)) {
    return;
  }
  Player player=Bukkit.getPlayer(args.get(0));
  if (player == null) {
    Element e=Element.getType(getElement(args.get(0)));
    if (e != null && sender instanceof Player) {
      if (GeneralMethods.getBendingPlayer(sender.getName()).hasElement(e)) {
        GeneralMethods.getBendingPlayer(sender.getName()).getElements().remove(e);
        GeneralMethods.saveElements(GeneralMethods.getBendingPlayer(sender.getName()));
        GeneralMethods.removeUnusableAbilities(sender.getName());
        if (e == Element.Chi) {
          sender.sendMessage(ChiMethods.getChiColor() + "String_Node_Str");
          return;
        }
        sender.sendMessage(GeneralMethods.getElementColor(e) + "String_Node_Str" + e.toString().toLowerCase()+ "String_Node_Str");
        return;
      }
 else {
        sender.sendMessage(ChatColor.RED + "String_Node_Str");
        return;
      }
    }
    sender.sendMessage(ChatColor.RED + "String_Node_Str");
    return;
  }
  BendingPlayer bPlayer=GeneralMethods.getBendingPlayer(player.getName());
  if (bPlayer == null) {
    GeneralMethods.createBendingPlayer(player.getUniqueId(),player.getName());
    bPlayer=GeneralMethods.getBendingPlayer(player.getName());
  }
  if (args.size() == 2) {
    Element e=Element.getType(getElement(args.get(1)));
    if (e != null) {
      if (!bPlayer.hasElement(e)) {
        sender.sendMessage(ChatColor.DARK_RED + "String_Node_Str");
        return;
      }
      bPlayer.getElements().remove(e);
      GeneralMethods.saveElements(bPlayer);
      GeneralMethods.removeUnusableAbilities(player.getName());
      if (e == Element.Chi) {
        sender.sendMessage(ChiMethods.getChiColor() + "String_Node_Str" + ChatColor.DARK_AQUA+ player.getName());
        player.sendMessage(ChiMethods.getChiColor() + "String_Node_Str" + ChatColor.DARK_AQUA+ sender.getName());
      }
 else {
        sender.sendMessage(GeneralMethods.getElementColor(e) + "String_Node_Str" + getElement(args.get(1)).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ player.getName());
        player.sendMessage(GeneralMethods.getElementColor(e) + "String_Node_Str" + getElement(args.get(1)).toLowerCase()+ "String_Node_Str"+ ChatColor.DARK_AQUA+ sender.getName());
      }
      Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,e,Result.REMOVE));
      return;
    }
  }
 else   if (args.size() == 1) {
    bPlayer.getElements().clear();
    GeneralMethods.saveElements(bPlayer);
    GeneralMethods.removeUnusableAbilities(player.getName());
    sender.sendMessage(ChatColor.YELLOW + "String_Node_Str" + ChatColor.DARK_AQUA+ player.getName());
    player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + ChatColor.DARK_AQUA+ sender.getName());
    Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,null,Result.REMOVE));
  }
}