Caught exception in OnEvent() for event code 200:

eligolf
2021-11-05 11:16:46

Hi,

Thank you for an awesome product, love it so far! I am having some weird issues with RPC calls however and I constantly (and sort of randomly?) get the following error message when playing with 3 players:

Caught exception in OnEvent() for event code 200: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.

It happens when I call my RPC function as per below which handles when a player finishes the hole in my minigolf game and lets all other player know it happened:

photonView.RPC(nameof(RPC_FinishedHole), RpcTarget.Others);    

...    

[PunRPC]    
  private void RPC_FinishedHole(PhotonMessageInfo info)    
  {    
    for (int i = 0; i < courseController.playerObjectsInGame.Count; i++)    
    {    
      GameObject player = courseController.playerObjectsInGame[i];    

      if (player.GetComponent<PhotonView>().Owner.UserId == info.Sender.UserId)    
      {    
        // Change status of the ball and remove player from list    
        player.GetComponent<Ball>().isBallInHole = true;    
        courseController.playerObjectsInGame.Remove(player);    
        break;    
      }    
    }    

    // Check if it was the last player on the hole    
    courseController.CheckForHoleEnded();    
  }    

playerObjectsInGame is how many players who are still playing the hole and havent finished. I go through the objects and see if I found the sending person. If I did, I set some parameters and then remove from the list of gameobjects. Lastly I check if the hole ended (if the list of playerObjectsInGame is <= 0.

Why is the error occuring? I have googled a lot but can't find any relevant reasons. Am I doing something wrong?

Comments

[Deleted User]
2021-11-12 16:05:13

Hello,

An exception was thrown in your RPC function. Check for any NullRefException, especially in your following lines :

for (int i = 0; i < courseController.playerObjectsInGame.Count; i++) //-> check if courseController or playerObjectsInGame are null    
player.GetComponent<PhotonView>().Owner.UserId == info.Sender.UserId //-> check if you get a photon view from player, check if Owner, info and Sender are null    
player.GetComponent<Ball>().isBallInHole = true; //-> check if you get a Ball from player    

eligolf
2021-11-13 07:56:14

Thanks Clemanza, I didn't know it was a null reference. That makes it easier to debug :)

maxclark
2023-01-30 23:28:56

Is there any better way of getting a stack trace from Photon rather than ust "somewhere in the excecution of this RPC there's a exception"?

Sometimes, my RPCs have large bodies and pinpointing where the null reference is is a headahce.

If I wrap the code in a try-block, then I get the line number for the source of the exception, but I don't want to have to wrap all my RPCs in try-catch blocks.