Network Manager fails to spawn local NetworkObjects on client

[Squashi11]

Description

Network Manager fails to spawn NetworkObjects with suspicious Hash ID on client connect

Reproduce Steps

( we have already tried :

1. Deleting and regenerating the Network Prefabs list)

2. Start host and spawn network objects (many of them)

3. Join a client

4. Client displays error in console

Actual Outcome

Network Object is not spawned locally on client

Expected Outcome

Network Object is spawned locally on client

Screenshots

Environment

• OS: Windows 11
• Unity Version: 6000.3.11f1
• Netcode Version: 2.10.0
• Netcode Commit: x
• Netcode Topology: Client Server

Additional Context

Why don't the error logs display the name of the problematic object / prefab?

There are also more errors happening but we will create a new Issue for them (Invalid Destroy)

[Squashi11]

I created a bug report with some reproduction steps ! CASE IN-137819
Feel free to reach me with more questions

[NoelStephensUnity]

Hi @Squashi11,

Based on the screenshot of the call-stack provided, it would appear that you are having issues (most likely) with in-scene placed NetworkObjects while the integrated scene management is disabled.

Does your project need a customized scene management solution?

If your project does not need a customized scene management solution:
I would recommend re-enabling scene management on the NetworkManager and see if that resolves your issue.

If your project does need a customized scene management solution:
Then you might be running into some of the issues that the integrated scene management solution solves for you. The typical issue one runs into has to do with in-scene placed NetworkObjects.

Synchronizing in-scene placed NetworkObjects is tricky, but you can look through the NetworkSceneManager to see how the integrated scene manager handles this.

Either case, this kind of error is actually expected if there is no existing custom scene management solution in place to handle synchronizing clients. If you still need to do this and are running into issues implementing your own scene management solution, feel free to post here with any questions you might have about that.

[Squashi11]

Thanks for the quick reply!
We spawn all object during playtime and there are only 2-3 scene objects that are network objects for NetworkBehaviour RPCs

The issue seems to still persist even after enabling Scene Management
We do not load unload any scenes, the scene stays the same during the whole game and only the gameObjects spawn / despawn

All the scene network objects are prefabs that are registered in the list

[NoelStephensUnity]

Oh... yeah...

So... when you created your MultiplayerRPC in-scene placed NetworkObject in your MainScene... is that the original that was used to actually create the prefab? (as outlined in the getting started section)

If so, I would delete that instance in your MainScene and drag and drop an instance of the MultiplayerRPC prefab you created into the scene. Then give that a try.

I was able to replicate your error message by:

• Creating a network prefab:
  • Create an empty GameObject.
  • Add a NetworkObject to it (and any other NetworkBehaviour component).
  • Drag that in-scene instance into the prefab folder.
  • What I skipped:
    • Deleting the in-scene instance used to create the prefab.
    • Adding an instance of the prefab created by dragging and dropping the newly created prefab into the same scene.

This gave me errors about not being able to find the prefab instance.

However, if I then perform the steps I skipped above and then connect a client to a session it spawns correctly.
(This was with scene management disabled, but I am sure this applies when scene management is enabled)