ConnectUsingSettings Error

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

///

/// This scirpt is used to connect and check if we are connected before start loading PHP scripts, this is only a template due we don't connect to any server.
///

public class NetworkManager : MonoBehaviour {


public bool connected; //Boolean that checks if we are connected to a server.

public Message _message; //A reference to our Message script

public string serverIP = "XXX.X.X.X"; //Server IP that will change by calling the "SelectServer" method from a button.

public GameObject[] ToEnableWhenConnect; //An Array of GameObject that must be enabled we've just connected to a server
public GameObject[] ToDisableWhenConnect; //The same, but this time the GameObject must be disabled!


private void Awake()
{
DontDestroyOnLoad(gameObject);
}

//This method is called by a UI button with the Server name and Server info.
public void SelectServer(string IP)
{
serverIP = IP;
}


//This method gonna be called when we press "Continue" from the server list.
public void SelectionServerContinue()
{
_message.gameObject.SetActive(true); //Poup up the message
_message.ChangeMessage("Connecting..."); //Change the message text

//Connect to the server with the ServerIP

PhotonNetwork.ConnectUsingSettings ("1.0.0");


if (connected)
{
//if we are connected, enable what we have to enable and disable what we have to disable
for (int i = 0; i < ToEnableWhenConnect.Length; i++)
{
ToEnableWhenConnect[i].SetActive(true);
}
for (int i = 0; i < ToDisableWhenConnect.Length; i++)
{
ToDisableWhenConnect[i].SetActive(false);
}
}
else //otherwise there was a problem with the connection, throw an error
{
_message.gameObject.SetActive(true);
_message.ChangeMessage("Could not reach this server, please check your connection and retry.");
return;
}
}


}