Program: 84997
Project: 84997
Buggy source:
public void onPlayerCommand(PlayerChatEvent event){
  Player player=event.getPlayer();
  String[] split=event.getMessage().split("String_Node_Str");
  String playerName=player.getName();
  if (mcUsers.getProfile(player).inParty() && split[0].equalsIgnoreCase("String_Node_Str")) {
    if (split.length < 2) {
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    if (isPlayer(split[1])) {
      Player target=getPlayer(split[1]);
      player.teleportTo(target);
      player.sendMessage(ChatColor.GREEN + "String_Node_Str" + target.getName());
      target.sendMessage(ChatColor.GREEN + player.getName() + "String_Node_Str");
    }
  }
  if (player.isOp() && split[0].equalsIgnoreCase("String_Node_Str")) {
    if (split.length < 2) {
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    if (isPlayer(split[1])) {
      Player target=getPlayer(split[1]);
      double x, y, z;
      x=target.getLocation().getX();
      y=target.getLocation().getY();
      z=target.getLocation().getZ();
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage(target.getName());
      player.sendMessage("String_Node_Str" + target.getHealth() + ChatColor.GRAY+ "String_Node_Str");
      player.sendMessage("String_Node_Str" + target.isOp());
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage("String_Node_Str" + mcUsers.getProfile(target).getgather());
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage("String_Node_Str" + x);
      player.sendMessage("String_Node_Str" + y);
      player.sendMessage("String_Node_Str" + z);
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    double x=player.getLocation().getX();
    double y=player.getLocation().getY();
    double z=player.getLocation().getZ();
    mcUsers.getProfile(player).setMySpawn(x,y,z);
    player.sendMessage(ChatColor.DARK_AQUA + "String_Node_Str");
  }
  if (player.isOp() && split[0].equalsIgnoreCase("String_Node_Str")) {
    spawn=event.getPlayer().getLocation();
    player.sendMessage("String_Node_Str");
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    event.setCancelled(true);
    player.sendMessage(ChatColor.DARK_GREEN + "String_Node_Str");
    player.sendMessage(ChatColor.DARK_GREEN + "String_Node_Str" + mcUsers.getProfile(player).getgather());
    player.sendMessage(ChatColor.GRAY + "String_Node_Str");
    player.sendMessage(ChatColor.GRAY + "String_Node_Str");
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    event.setCancelled(true);
    if (split.length == 1 && !mcUsers.getProfile(player).inParty()) {
      player.sendMessage("String_Node_Str");
      return;
    }
    if (split.length == 1 && mcUsers.getProfile(player).inParty()) {
      String tempList="String_Node_Str";
      int x=0;
      for (      Player p : plugin.getServer().getOnlinePlayers()) {
        if (mcUsers.getProfile(player).getParty().equals(mcUsers.getProfile(p).getParty())) {
          if (p != null && x + 1 >= partyCount(player)) {
            tempList+=p.getName();
            x++;
          }
          if (p != null && x < partyCount(player)) {
            tempList+=p.getName() + "String_Node_Str";
            x++;
          }
        }
      }
      player.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.WHITE+ tempList+ ChatColor.GREEN+ "String_Node_Str");
    }
    if (split[1].equals("String_Node_Str") && mcUsers.getProfile(player).inParty()) {
      informPartyMembersQuit(player);
      mcUsers.getProfile(player).removeParty();
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    mcUsers.getProfile(player).setParty(split[1]);
    player.sendMessage("String_Node_Str" + split[1]);
    informPartyMembers(player);
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    if (mcConfig.getInstance().isAdminToggled(player.getName()))     mcConfig.getInstance().toggleAdminChat(playerName);
    mcConfig.getInstance().togglePartyChat(playerName);
    if (mcConfig.getInstance().isPartyToggled(playerName)) {
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
    }
 else {
      player.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.RED+ "String_Node_Str");
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str") && player.isOp()) {
    if (mcConfig.getInstance().isPartyToggled(player.getName()))     mcConfig.getInstance().togglePartyChat(playerName);
    mcConfig.getInstance().toggleAdminChat(playerName);
    if (mcConfig.getInstance().isAdminToggled(playerName)) {
      player.sendMessage(ChatColor.AQUA + "String_Node_Str" + ChatColor.GREEN+ "String_Node_Str");
    }
 else {
      player.sendMessage(ChatColor.AQUA + "String_Node_Str" + ChatColor.RED+ "String_Node_Str");
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    player.getInventory().clear();
    player.setHealth(20);
    player.teleportTo(mcUsers.getProfile(player).getMySpawn(player));
    player.sendMessage("String_Node_Str");
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    if (spawn != null) {
      player.teleportTo(spawn);
      player.sendMessage("String_Node_Str");
      return;
    }
    player.sendMessage("String_Node_Str");
  }
}

Fixed version (ground truth):
public void onPlayerCommand(PlayerChatEvent event){
  Player player=event.getPlayer();
  String[] split=event.getMessage().split("String_Node_Str");
  String playerName=player.getName();
  if (mcUsers.getProfile(player).inParty() && split[0].equalsIgnoreCase("String_Node_Str")) {
    if (split.length < 2) {
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    if (isPlayer(split[1])) {
      Player target=getPlayer(split[1]);
      if (mcUsers.getProfile(player).getParty().equals(mcUsers.getProfile(target).getParty())) {
        player.teleportTo(target);
        player.sendMessage(ChatColor.GREEN + "String_Node_Str" + target.getName());
        target.sendMessage(ChatColor.GREEN + player.getName() + "String_Node_Str");
      }
    }
  }
  if (player.isOp() && split[0].equalsIgnoreCase("String_Node_Str")) {
    if (split.length < 2) {
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    if (isPlayer(split[1])) {
      Player target=getPlayer(split[1]);
      double x, y, z;
      x=target.getLocation().getX();
      y=target.getLocation().getY();
      z=target.getLocation().getZ();
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage(target.getName());
      player.sendMessage("String_Node_Str" + target.getHealth() + ChatColor.GRAY+ "String_Node_Str");
      player.sendMessage("String_Node_Str" + target.isOp());
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage("String_Node_Str" + mcUsers.getProfile(target).getMining());
      player.sendMessage("String_Node_Str" + mcUsers.getProfile(target).getWoodCutting());
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
      player.sendMessage("String_Node_Str" + x);
      player.sendMessage("String_Node_Str" + y);
      player.sendMessage("String_Node_Str" + z);
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    double x=player.getLocation().getX();
    double y=player.getLocation().getY();
    double z=player.getLocation().getZ();
    mcUsers.getProfile(player).setMySpawn(x,y,z);
    player.sendMessage(ChatColor.DARK_AQUA + "String_Node_Str");
  }
  if (player.isOp() && split[0].equalsIgnoreCase("String_Node_Str")) {
    spawn=event.getPlayer().getLocation();
    player.sendMessage("String_Node_Str");
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    event.setCancelled(true);
    player.sendMessage(ChatColor.DARK_GREEN + "String_Node_Str");
    player.sendMessage(ChatColor.DARK_GREEN + "String_Node_Str" + mcUsers.getProfile(player).getMining());
    player.sendMessage(ChatColor.DARK_GREEN + "String_Node_Str" + mcUsers.getProfile(player).getWoodCutting());
    player.sendMessage(ChatColor.GRAY + "String_Node_Str");
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    event.setCancelled(true);
    if (split.length == 1 && !mcUsers.getProfile(player).inParty()) {
      player.sendMessage("String_Node_Str");
      return;
    }
    if (split.length == 1 && mcUsers.getProfile(player).inParty()) {
      String tempList="String_Node_Str";
      int x=0;
      for (      Player p : plugin.getServer().getOnlinePlayers()) {
        if (mcUsers.getProfile(player).getParty().equals(mcUsers.getProfile(p).getParty())) {
          if (p != null && x + 1 >= partyCount(player)) {
            tempList+=p.getName();
            x++;
          }
          if (p != null && x < partyCount(player)) {
            tempList+=p.getName() + "String_Node_Str";
            x++;
          }
        }
      }
      player.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.WHITE+ tempList+ ChatColor.GREEN+ "String_Node_Str");
    }
    if (split[1].equals("String_Node_Str") && mcUsers.getProfile(player).inParty()) {
      informPartyMembersQuit(player);
      mcUsers.getProfile(player).removeParty();
      player.sendMessage(ChatColor.RED + "String_Node_Str");
      return;
    }
    mcUsers.getProfile(player).setParty(split[1]);
    player.sendMessage("String_Node_Str" + split[1]);
    informPartyMembers(player);
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    if (mcConfig.getInstance().isAdminToggled(player.getName()))     mcConfig.getInstance().toggleAdminChat(playerName);
    mcConfig.getInstance().togglePartyChat(playerName);
    if (mcConfig.getInstance().isPartyToggled(playerName)) {
      player.sendMessage(ChatColor.GREEN + "String_Node_Str");
    }
 else {
      player.sendMessage(ChatColor.GREEN + "String_Node_Str" + ChatColor.RED+ "String_Node_Str");
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str") && player.isOp()) {
    if (mcConfig.getInstance().isPartyToggled(player.getName()))     mcConfig.getInstance().togglePartyChat(playerName);
    mcConfig.getInstance().toggleAdminChat(playerName);
    if (mcConfig.getInstance().isAdminToggled(playerName)) {
      player.sendMessage(ChatColor.AQUA + "String_Node_Str" + ChatColor.GREEN+ "String_Node_Str");
    }
 else {
      player.sendMessage(ChatColor.AQUA + "String_Node_Str" + ChatColor.RED+ "String_Node_Str");
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    if (mcUsers.getProfile(player).getMySpawn(player) != null) {
      player.getInventory().clear();
      player.setHealth(20);
      player.teleportTo(mcUsers.getProfile(player).getMySpawn(player));
      player.sendMessage("String_Node_Str");
    }
 else {
      player.sendMessage(ChatColor.RED + "String_Node_Str");
    }
  }
  if (split[0].equalsIgnoreCase("String_Node_Str")) {
    if (spawn != null) {
      player.teleportTo(spawn);
      player.sendMessage("String_Node_Str");
      return;
    }
    player.sendMessage("String_Node_Str");
  }
}