strange error

Hi guys, i have a strange error...

Internal compiler error. See the console log for more information. output was: Unhandled Exception: System.TypeLoadException: Could not load type 'System.Func`1' from assembly 'mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'.

the code is:

 using UnityEngine;
 using System.Collections;
 
 public class NetworkManager : MonoBehaviour {
 
     public Camera standbyCamera;
     SpawnSpot[] spawnSpots;
 
 
     // Use this for initialization                                
     void Start () 
     {
         spawnSpots = GameObject.FindObjectsOfType<SpawnSpot>();
         Connect ();
     }
     
     // Update is called once per frame
     void Connect () 
     {
         PhotonNetwork.ConnectUsingSettings ("1.0");
     }
 
     void OnGUI ()
     {
         GUILayout.Label (PhotonNetwork.connectionStateDetailed.ToString ());
     }
 
     void OnJoinedLobby ()
     {
         PhotonNetwork.JoinRandomRoom ();
     }
 
     void OnPhotonRandomJoinFailed()
     {
         PhotonNetwork.CreateRoom (null);
     }
 
     void OnJoinedRoom()
     {
         SpawnMyPlayer ();
     }
 
     void SpawnMyPlayer ()
     {
         if (spawnSpots == null) 
         {
             Debug.LogError ("HellStarted");
         }
         SpawnSpot mySpawnSpot = spawnSpots [Random.Range (0, spawnSpots.Length)];
         PhotonNetwork.Instantiate("PlayerController", mySpawnSpot.transform.position,  mySpawnSpot.transform.rotation , 0);
         standbyCamera.enabled = false;
     }
 
 
 }

i´d be very nice if you could help me <3