Unity Networking - Error on spawning Player

 NullReferenceException
 UnityEngine.Network.Instantiate (UnityEngine.Object prefab, Vector3 position, Quaternion rotation, Int32 group) (at C:/BuildAgent/work/d3d49558e4d408f4/artifacts/EditorGenerated/Networking.cs:627)
 NetworkHandler.spawnPlayer () (at Assets/Scripts/NetworkHandler.cs:49)
 NetworkHandler.OnGUI () (at Assets/Scripts/NetworkHandler.cs:85)

That is the error I am receiving when I try to join a server

NetworkHandler.CS

 using UnityEngine;
 using System.Collections;
 
 public class NetworkHandler : MonoBehaviour {
 
     string registeredGameName = "Warlords_Of_Space_Prototype";
 
     float refreshRequestLenghth = 3.0f;
 
     HostData[] hostData;
 
     int port = 21025;
 
 
     private void startServer()
     {
         Network.InitializeServer (16, port, false);
         MasterServer.RegisterHost (registeredGameName, "Master Server");
     }
 
 
 
     void OnMasterServerEvent(MasterServerEvent masterServerEvent)
     {
         if (masterServerEvent == MasterServerEvent.RegistrationSucceeded) {
             Debug.Log ("Registration successful!");        
         }
     }
 
     public IEnumerator RefreshHostList()
     {
         Debug.Log ("Refreshing.");
         MasterServer.RequestHostList (registeredGameName);
 
         float timeEnd = Time.time + refreshRequestLenghth;
         while (Time.time<timeEnd) {
           hostData = MasterServer.PollHostList ();
             yield return new WaitForEndOfFrame();
                 }
         if (hostData == null || hostData.Length == 0) {
             Debug.Log("no active servers");        
         }else
             Debug.Log(hostData.Length + " server(s) found");
         }
 
     private void spawnPlayer()
     {
         Debug.Log ("Spawning Player");
         Network.Instantiate(Resources.Load ("Prefabs/pShip"), new Vector3(0f,2.5f,0f), Quaternion.identity, 1);
     }
 
     void OnServerInitalize()
     {
         Debug.Log ("Server has been initialized");
         spawnPlayer ();
     }
 
     void OnPlayerDisconnected(NetworkPlayer player)
     {
         Network.RemoveRPCs (player);
         Network.DestroyPlayerObjects (player);
     }
 
     void OnApplicationQuit()
     {
         if (Network.isServer) {
             Network.Disconnect(200);
             MasterServer.UnregisterHost();
         
         }
         if (Network.isClient) {
             Network.Disconnect(200);        
         }
         }
 
     public void OnGUI()
     {
         if (Network.isServer) {
                 
             GUILayout.Label("Running as a server.");
         }
 
         if (Network.isClient) {
             GUILayout.Label("Running as a client.");
             spawnPlayer();
                 }
 
                 if (Network.isClient || Network.isServer) {
                         return;
                 }
 
                 if (GUI.Button (new Rect (25f, 25f, 150f, 30f), "Start New Server")) {
                         
                         startServer ();
                         //Application.LoadLevel ("Game");
                         
                 }
                 if (GUI.Button (new Rect (25f, 65f, 150f, 30f), "Refresh Server List")) {
                         StartCoroutine ("RefreshHostList");
                 }
                 if (hostData != null) {
                         for (int i = 0; i< hostData.Length; i++) {
                                 if (GUI.Button (new Rect (Screen.width / 2, 65 + (30 * i), 300f, 30f), hostData [i].gameName)) {
                                     Network.Connect(hostData[i]);
                                 }
                         }
                 }
         }
 }

The Error seems to be this line here: Network.Instantiate(Resources.Load ("Prefabs/pShip"), new Vector3(0f,2.5f,0f), Quaternion.identity, 1);

Could anyone help me solve this?