main Camera Not Getting activeated

Hey guys i have a problem with The player Main Camera it will not activate when my player spawns i think its becouse its set to Active false but i dont know how to fix this

its for my multiplayer game but when i spawn nothing happends

its in this line

 myPlayerGO.transform.FindChild("MainCamera").gameObject.SetActive(true);
 
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     public void SpawnMyPlayer ()  {
             if(spawnSpots == null)
             {
                 Debug.LogError("ERROR");
                 return;
     
             }
     
             SpawnSpotNetwerk mySpawnSpot = spawnSpots[Random.Range (0, spawnSpots.Length) ];
             GameObject myPlayerGO = (GameObject)PhotonNetwork.Instantiate("SpartanPlayer", mySpawnSpot.transform.position, mySpawnSpot.transform.rotation, 0);
             // GameObject myPlayerGO = (GameObject)PhotonNetwork.Instantiate("SpartanPlayerMecanim", mySpawnSpot.transform.position, mySpawnSpot.transform.rotation, 0);
             standbyCamera.SetActive(false);
     
             myPlayerGO.GetComponent<RigidbodyFirstPersonController>().enabled = true;
             //myPlayerGO.GetComponent<PlayerMovement>().enabled = true;//for mecanim player
             //myPlayerGO.GetComponent<MouseLook>().enabled = true;
             myPlayerGO.GetComponent<PlayerHealth>().enabled = true;
             //myPlayerGO.GetComponent<RocketLouncherShoot>().enabled = true;
             myPlayerGO.transform.FindChild("Spartan").gameObject.layer = 10;
             myPlayerGO.transform.FindChild("MainCamera").gameObject.SetActive(true);
             Debug.Log("MaincamActive");
             myPlayerGO.GetComponent<UnityStandardAssets.ImageEffects.BloomAndFlares>().enabled = true;
             myPlayerGO.GetComponent<UnityStandardAssets.ImageEffects.SunShafts>().enabled = true;
             //myPlayerGO.transform.FindChild("GunCam").gameObject.SetActive(true);
             //myPlayerGO.transform.FindChild("Spartan").gameObject.SetActive(false);
         }
     }