Program: 133875
Project: 133875
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) {
    if (args.size() == 1) {
      Element e=Element.fromString(args.get(0));
      BendingPlayer senderBPlayer=BendingPlayer.getBendingPlayer(sender.getName());
      if (senderBPlayer != null && sender instanceof Player) {
        if (e != null) {
          if (e instanceof SubElement) {
            if (senderBPlayer.hasElement(e)) {
              senderBPlayer.getSubElements().remove(e);
              GeneralMethods.saveSubElements(senderBPlayer);
              GeneralMethods.removeUnusableAbilities(sender.getName());
              sender.sendMessage(e.getColor() + this.succesfullyRemovedElementSelf.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + e.getColor()));
              Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeSubElementEvent(sender,player,(SubElement)e,com.projectkorra.projectkorra.event.PlayerChangeSubElementEvent.Result.REMOVE));
            }
 else             sender.sendMessage(ChatColor.RED + wrongElementSelf);
            return;
          }
 else           if (e instanceof Element) {
            if (senderBPlayer.hasElement(e)) {
              senderBPlayer.getElements().remove(e);
              GeneralMethods.saveElements(senderBPlayer);
              GeneralMethods.removeUnusableAbilities(sender.getName());
              sender.sendMessage(e.getColor() + succesfullyRemovedElementSelf.replace("String_Node_Str",e.getName()));
              Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,(Player)sender,e,Result.REMOVE));
              return;
            }
 else             sender.sendMessage(ChatColor.RED + wrongElementSelf);
{
              return;
            }
          }
        }
 else         sender.sendMessage(ChatColor.RED + invalidElement);
{
          return;
        }
      }
      sender.sendMessage(ChatColor.RED + playerOffline);
      return;
    }
 else {
      help(sender,false);
      return;
    }
  }
  BendingPlayer bPlayer=BendingPlayer.getBendingPlayer(player);
  if (bPlayer == null) {
    GeneralMethods.createBendingPlayer(player.getUniqueId(),player.getName());
    bPlayer=BendingPlayer.getBendingPlayer(player);
  }
  if (args.size() == 2) {
    Element e=Element.fromString(args.get(1));
    if (e != null) {
      if (!bPlayer.hasElement(e)) {
        sender.sendMessage(ChatColor.DARK_RED + wrongElementTarget.replace("String_Node_Str",player.getName()));
        return;
      }
      if (e instanceof SubElement) {
        bPlayer.getSubElements().remove(e);
        GeneralMethods.saveSubElements(bPlayer);
      }
 else {
        bPlayer.getElements().remove(e);
        GeneralMethods.saveElements(bPlayer);
      }
      GeneralMethods.removeUnusableAbilities(player.getName());
      player.sendMessage(e.getColor() + this.succesfullyRemovedElementTargetConfirm.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + player.getName() + e.getColor()));
      sender.sendMessage(e.getColor() + this.succesfullyRemovedElementTarget.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + e.getColor()));
      Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,e,Result.REMOVE));
      return;
    }
  }
 else   if (args.size() == 1) {
    bPlayer.getElements().clear();
    bPlayer.getSubElements().clear();
    GeneralMethods.saveElements(bPlayer);
    GeneralMethods.saveSubElements(bPlayer);
    GeneralMethods.removeUnusableAbilities(player.getName());
    if (GeneralMethods.hasRPG())     RPGMethods.revokeAvatar(bPlayer.getUUID());
    if (!player.getName().equalsIgnoreCase(sender.getName()))     sender.sendMessage(ChatColor.YELLOW + this.succesfullyRemovedAllElementsTargetConfirm.replace("String_Node_Str",ChatColor.DARK_AQUA + player.getName() + ChatColor.YELLOW));
    player.sendMessage(ChatColor.YELLOW + this.succesfullyRemovedAllElementsTarget.replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + ChatColor.YELLOW));
    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) {
    if (args.size() == 1) {
      Element e=Element.fromString(args.get(0));
      BendingPlayer senderBPlayer=BendingPlayer.getBendingPlayer(sender.getName());
      if (senderBPlayer != null && sender instanceof Player) {
        if (e != null) {
          if (e instanceof SubElement) {
            if (senderBPlayer.hasElement(e)) {
              senderBPlayer.getSubElements().remove(e);
              GeneralMethods.saveSubElements(senderBPlayer);
              GeneralMethods.removeUnusableAbilities(sender.getName());
              sender.sendMessage(e.getColor() + this.succesfullyRemovedElementSelf.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + e.getColor()));
              Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeSubElementEvent(sender,player,(SubElement)e,com.projectkorra.projectkorra.event.PlayerChangeSubElementEvent.Result.REMOVE));
            }
 else             sender.sendMessage(ChatColor.RED + wrongElementSelf);
            return;
          }
 else           if (e instanceof Element) {
            if (senderBPlayer.hasElement(e)) {
              senderBPlayer.getElements().remove(e);
              GeneralMethods.saveElements(senderBPlayer);
              GeneralMethods.removeUnusableAbilities(sender.getName());
              sender.sendMessage(e.getColor() + succesfullyRemovedElementSelf.replace("String_Node_Str",e.getName()));
              Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,(Player)sender,e,Result.REMOVE));
              return;
            }
 else             sender.sendMessage(ChatColor.RED + wrongElementSelf);
{
              return;
            }
          }
        }
 else         sender.sendMessage(ChatColor.RED + invalidElement);
{
          return;
        }
      }
      sender.sendMessage(ChatColor.RED + playerOffline);
      return;
    }
 else {
      help(sender,false);
      return;
    }
  }
  BendingPlayer bPlayer=BendingPlayer.getBendingPlayer(player);
  if (bPlayer == null) {
    GeneralMethods.createBendingPlayer(player.getUniqueId(),player.getName());
    bPlayer=BendingPlayer.getBendingPlayer(player);
  }
  if (args.size() == 2) {
    Element e=Element.fromString(args.get(1));
    if (e != null) {
      if (!bPlayer.hasElement(e)) {
        sender.sendMessage(ChatColor.DARK_RED + wrongElementTarget.replace("String_Node_Str",player.getName()));
        return;
      }
      if (e instanceof SubElement) {
        bPlayer.getSubElements().remove(e);
        GeneralMethods.saveSubElements(bPlayer);
      }
 else {
        bPlayer.getElements().remove(e);
        GeneralMethods.saveElements(bPlayer);
      }
      GeneralMethods.removeUnusableAbilities(player.getName());
      player.sendMessage(e.getColor() + this.succesfullyRemovedElementTarget.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + e.getColor()));
      sender.sendMessage(e.getColor() + this.succesfullyRemovedElementTargetConfirm.replace("String_Node_Str",e.getName() + e.getType().getBending()).replace("String_Node_Str",ChatColor.DARK_AQUA + player.getName() + e.getColor()));
      Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,e,Result.REMOVE));
      return;
    }
  }
 else   if (args.size() == 1) {
    bPlayer.getElements().clear();
    bPlayer.getSubElements().clear();
    GeneralMethods.saveElements(bPlayer);
    GeneralMethods.saveSubElements(bPlayer);
    GeneralMethods.removeUnusableAbilities(player.getName());
    if (GeneralMethods.hasRPG())     RPGMethods.revokeAvatar(bPlayer.getUUID());
    if (!player.getName().equalsIgnoreCase(sender.getName()))     sender.sendMessage(ChatColor.YELLOW + this.succesfullyRemovedAllElementsTargetConfirm.replace("String_Node_Str",ChatColor.DARK_AQUA + player.getName() + ChatColor.YELLOW));
    player.sendMessage(ChatColor.YELLOW + this.succesfullyRemovedAllElementsTarget.replace("String_Node_Str",ChatColor.DARK_AQUA + sender.getName() + ChatColor.YELLOW));
    Bukkit.getServer().getPluginManager().callEvent(new PlayerChangeElementEvent(sender,player,null,Result.REMOVE));
  }
}