Program: 133821
Project: 133821
Buggy source:
/** 
 * Displays the enabled moves for the given element to the CommandSender.
 * @param sender The CommandSender to show the moves to
 * @param element The element to show the moves for
 */
private void displayElement(CommandSender sender,Element element){
  List<CoreAbility> abilities=CoreAbility.getAbilitiesByElement(element);
  if (abilities.isEmpty()) {
    sender.sendMessage(ChatColor.RED + invalidArgument);
    return;
  }
 else   if (abilities.isEmpty()) {
    sender.sendMessage(ChatColor.YELLOW + noAbilitiesAvailable.replace("String_Node_Str",element.getColor() + element.getName() + ChatColor.YELLOW));
  }
  for (  CoreAbility ability : abilities) {
    if (ability instanceof SubAbility || ability.isHiddenAbility()) {
      continue;
    }
    if (!(sender instanceof Player) || GeneralMethods.canView((Player)sender,ability.getName())) {
      sender.sendMessage(ability.getElement().getColor() + ability.getName());
    }
  }
  if (element.equals(Element.CHI)) {
    sender.sendMessage(ChatColor.GOLD + "String_Node_Str" + ChatColor.YELLOW+ "String_Node_Str");
  }
 else {
    sender.sendMessage(element.getSubColor() + "String_Node_Str" + element.getColor()+ "String_Node_Str"+ element.getName()+ "String_Node_Str");
    for (    SubElement sub : Element.getSubElements(element)) {
      if (sender.hasPermission("String_Node_Str" + element.getName().toLowerCase() + "String_Node_Str"+ sub.getName().toLowerCase())) {
        sender.sendMessage(sub.getColor() + sub.getName() + "String_Node_Str"+ element.getColor()+ "String_Node_Str"+ sub.getName());
      }
    }
  }
}

Fixed version (ground truth):
/** 
 * Displays the enabled moves for the given element to the CommandSender.
 * @param sender The CommandSender to show the moves to
 * @param element The element to show the moves for
 */
private void displayElement(CommandSender sender,Element element){
  List<CoreAbility> abilities=CoreAbility.getAbilitiesByElement(element);
  if (abilities.isEmpty()) {
    sender.sendMessage(ChatColor.RED + invalidArgument);
    return;
  }
 else   if (abilities.isEmpty()) {
    sender.sendMessage(ChatColor.YELLOW + noAbilitiesAvailable.replace("String_Node_Str",element.getColor() + element.getName() + ChatColor.YELLOW));
  }
  HashSet<String> abilitiesSent=new HashSet<String>();
  for (  CoreAbility ability : abilities) {
    if (ability instanceof SubAbility || ability.isHiddenAbility() || abilitiesSent.contains(ability.getName())) {
      continue;
    }
    if (!(sender instanceof Player) || GeneralMethods.canView((Player)sender,ability.getName())) {
      sender.sendMessage(ability.getElement().getColor() + ability.getName());
      abilitiesSent.add(ability.getName());
    }
  }
  if (element.equals(Element.CHI)) {
    sender.sendMessage(ChatColor.GOLD + "String_Node_Str" + ChatColor.YELLOW+ "String_Node_Str");
  }
 else {
    sender.sendMessage(element.getSubColor() + "String_Node_Str" + element.getColor()+ "String_Node_Str"+ element.getName()+ "String_Node_Str");
    for (    SubElement sub : Element.getSubElements(element)) {
      if (sender.hasPermission("String_Node_Str" + element.getName().toLowerCase() + "String_Node_Str"+ sub.getName().toLowerCase())) {
        sender.sendMessage(sub.getColor() + sub.getName() + "String_Node_Str"+ element.getColor()+ "String_Node_Str"+ sub.getName());
      }
    }
  }
}