no function mcreatorfor minecraft 1.7.10 with arduino

Hi good afternoon.
I have a notebook with win10.
have Minecraft 7.10 installed.

mcreator (1.7.10) was installed and can create blocks that work well. Now I wanted to test mcreator with the arduino:
https://mcreator.net/wiki/mcreator-arduino

have these two script taken for the block to keep sc:
-------------------------------------------------- -----------------------------
String msg = "on";
try {
  java.net.DatagramSocket socket = new java.net.DatagramSocket ();
  socket.send (new java.net.DatagramPacket ((msg + "" + (char) 13) .getBytes (),
     .getBytes (msg + "" + (char) 13) (). length,
     java.net.InetAddress.getByName ( "127.0.0.1") 5050));
  socket.close ();
} catch (Exception e) {}

-------------------------------------------------- -------

String msg = "off";
try {
  java.net.DatagramSocket socket = new java.net.DatagramSocket ();
  socket.send (new java.net.DatagramPacket ((msg + "" + (char) 13) .getBytes (),
     .getBytes (msg + "" + (char) 13) (). length,
     java.net.InetAddress.getByName ( "127.0.0.1") 5050));
  socket.close ();
} catch (Exception e) {}
-------------------------------------------------- ---------

"mcreator to arduino connector" is ok with "port 6".
but no data will be sent "udp> com" and
"com> udp" indicate nothing.
There are no serial data on the arduino.

Thank you.
greeting