Avoid Photon OnDestroy Warnings

I like my code to compile and run without errors.  The Photon Unity Networking (PUN) code did not.

When exiting scenes I would get the following errors for each instantiated object in the level:

OnDestroy for PhotonView View (0)1001 on CharacterPlaceholder(Clone)  but GO is still in instantiatedObjects. instantiationId: 1001. Use PhotonNetwork.Destroy().

Failed to 'network-remove' GameObject because it's null.


I searched the Internet and Exit Games forums but found little help that actually solved the problem. I found plenty of other people reporting the same issue.

I tried reading the PUN documentation but that was unhelpful as were any of the samples that I tried so I experimented.

I now have a work round which avoids the warnings and errors.

/// Tidies up before exit from the scene.
/// Attempts to destroy network objects correctly.
/// Pauses the messages while the scene changes.
private static void TidyUpBeforeExit()
{
  // Destroy any photonView game objects.
  PhotonView[] views = 
          GameObject.FindObjectsOfType<photonview>();

  // Whichever client exits first cannot 
  // destroy the objects owned by
  // another client.
  foreach (PhotonView view in views)
  {
    GameObject obj = view.gameObject;

    if (view.isMine)
    {
      // Clients can destroy their 
      // own instantiated objects
      PhotonNetwork.Destroy (obj);
    }
    else
    {
      // Clients cannot destroy objects 
      // instantiated by other clients.
      // This avoids the error by 
      // removing the instantiated 
      // object before the network view 
      // is destroyed
      if (PhotonNetwork.
            networkingPeer.
            instantiatedObjects.
            ContainsKey(view.instantiationId))
      {
        PhotonNetwork.
            networkingPeer.
            instantiatedObjects.
            Remove (view.instantiationId);
      }
    }
  }

  // By pausing and starting the 
  // messages manually I can start
  // any client or server in any 
  // order and all spawn messages
  // are retained.
  PhotonNetwork.SetSendingEnabled(0, false);
  PhotonNetwork.isMessageQueueRunning = false;
}

I simply include that method before any scene change.