Program: 1964
Project: 1964
Buggy source:
/** 
 * Creates an NPC given a string array, containing the name of the NPC and optional text to be added to it.
 * @param args
 * @param player
 */
private void create(String[] args,Player player){
  String text="String_Node_Str";
  ArrayList<String> texts=new ArrayList<String>();
  if (args.length >= 3) {
    int i=0;
    for (    String s : args) {
      if (i == 2 && !s.isEmpty() && !s.equals("String_Node_Str")) {
        text+=s;
      }
      if (i > 2 && !s.isEmpty() && !s.equals("String_Node_Str")) {
        text+="String_Node_Str" + s;
      }
      i+=1;
    }
    texts.add(text);
  }
  if (args[1].length() > 16) {
    player.sendMessage(ChatColor.RED + "String_Node_Str");
    return;
  }
  if ((PropertyManager.getBasic().getNPCAmountPerPlayer(player.getName()) < UtilityProperties.getMaxNPCsPerPlayer()) || (UtilityProperties.settings.getInt("String_Node_Str") == 0) || (Permission.hasPermission("String_Node_Str",(CommandSender)player))) {
    int UID=NPCManager.register(args[1],player.getLocation(),player.getName());
    PropertyManager.getBasic().saveNPCAmountPerPlayer(player.getName(),PropertyManager.getBasic().getNPCAmountPerPlayer(player.getName()) + 1);
    NPCManager.setText(UID,texts);
    NPCManager.get(UID).getNPCData().setOwner(player.getName());
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap(args[1])+ "String_Node_Str");
    if (EconomyHandler.useEconomy()) {
      double paid=EconomyHandler.pay(Operation.BASIC_NPC_CREATE,player);
      if (paid > 0) {
        player.sendMessage(MessageUtils.getPaidMessage(Operation.BASIC_NPC_CREATE,paid,args[1],"String_Node_Str",false));
      }
    }
    NPCManager.selectedNPCs.put(player.getName(),UID);
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap(args[1])+ "String_Node_Str"+ StringUtils.wrap(UID)+ "String_Node_Str");
  }
 else {
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap("String_Node_Str" + UtilityProperties.getMaxNPCsPerPlayer())+ "String_Node_Str");
  }
}

Fixed version (ground truth):
/** 
 * Creates an NPC given a string array, containing the name of the NPC and optional text to be added to it.
 * @param args
 * @param player
 */
private void create(String[] args,Player player){
  String text="String_Node_Str";
  ArrayList<String> texts=new ArrayList<String>();
  if (args.length >= 3) {
    int i=0;
    for (    String s : args) {
      if (i == 2 && !s.isEmpty() && !s.equals("String_Node_Str")) {
        text+=s;
      }
      if (i > 2 && !s.isEmpty() && !s.equals("String_Node_Str")) {
        text+="String_Node_Str" + s;
      }
      i+=1;
    }
    texts.add(text);
  }
  if (args[1].length() > 16) {
    player.sendMessage(ChatColor.RED + "String_Node_Str");
    return;
  }
  if ((PropertyManager.getBasic().getNPCAmountPerPlayer(player.getName()) < UtilityProperties.getMaxNPCsPerPlayer()) || (UtilityProperties.settings.getInt("String_Node_Str") == 0) || (Permission.hasPermission("String_Node_Str",(CommandSender)player))) {
    int UID=NPCManager.register(args[1],player.getLocation(),player.getName());
    PropertyManager.getBasic().saveNPCAmountPerPlayer(player.getName(),PropertyManager.getBasic().getNPCAmountPerPlayer(player.getName()) + 1);
    NPCManager.setText(UID,texts);
    NPCManager.get(UID).getNPCData().setOwner(player.getName());
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap(args[1])+ "String_Node_Str");
    if (EconomyHandler.useEconomy()) {
      double paid=EconomyHandler.pay(Operation.BASIC_CREATION,player);
      if (paid > 0) {
        player.sendMessage(MessageUtils.getPaidMessage(Operation.BASIC_CREATION,paid,args[1],"String_Node_Str",false));
      }
    }
    NPCManager.selectedNPCs.put(player.getName(),UID);
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap(args[1])+ "String_Node_Str"+ StringUtils.wrap(UID)+ "String_Node_Str");
  }
 else {
    player.sendMessage(ChatColor.GREEN + "String_Node_Str" + StringUtils.wrap("String_Node_Str" + UtilityProperties.getMaxNPCsPerPlayer())+ "String_Node_Str");
  }
}