Failed to connect to master server at - Help Pls

using UnityEngine;
using UnityEngine.Networking;
//using System.Net.Sockets;
using System.Net;
using System.Collections;
using System.IO;

public class serverNetwork : MonoBehaviour {

public string IPAdresim = "176.43.113.191";
public string HostIP = "127.0.0.1";
public int PortNo = 25001;
public string OyunADI = "arda_test_server1";
public string ServerADI = "ArdaGame";
//TcpListener tcp_Listener = null;


void OnGUI()
{

GUI.Label(new Rect(25f,...

Failed to connect to master server at - Help Pls