Detach but no longer active objects fail to set parent

[shadowfinderstudios]

General
Unity version: 6000.0.26f1
Fish-Networking version: 4.5.5R
Discord link: https://discord.com/channels/424284635074134018/851790045534748702/1308093185763049524

Description
When the game shuts down there is a possibility of an object that is no longer active but detached from the parent, as a result the SetParent is attempted on it but it isn't active in the hierarchy and causes an exception during shutdown. In addition, NetworkBehavior can attempt to OnDestroy an already null object during this time as well.

Replication
Steps to reproduce the behavior:

1. Create a lot of objects and play your game.
2. Suddenly shut down your game.
3. See the exceptions.

Expected behavior
No exceptions on shutdown.

Code to fix the issue
In ResetState() in ChildTransformTickSmoother.cs:

if (_detach && _graphicalObject.gameObject.activeInHierarchy) { _graphicalObject.SetParent(_rootTransform); }

And, in NetworkObject.cs change network destroy to:

void NetworkBehaviour_OnDestroy() { foreach (NetworkBehaviour nb in NetworkBehaviours) { if (nb != null) nb.NetworkBehaviour_OnDestroy(); } }

[FirstGearGames]

Can you elaborate on what parts you're adding these, or what lines you are modifying?

[shadowfinderstudios]

Not sure if line numbers will help as much since those can change.

In ResetState() in ChildTransformTickSmoother.cs at line 654, change :
if (_detach) { _graphicalObject.SetParent(_rootTransform); }

To:
if (_detach && _graphicalObject.gameObject.activeInHierarchy) { _graphicalObject.SetParent(_rootTransform); }

And, NetworkObject.cs line 533 in NetworkBehaviour_OnDestroy, change:

void NetworkBehaviour_OnDestroy() { foreach (NetworkBehaviour nb in NetworkBehaviours) { nb.NetworkBehaviour_OnDestroy(); } }

To:
void NetworkBehaviour_OnDestroy() { foreach (NetworkBehaviour nb in NetworkBehaviours) { if (nb != null) nb.NetworkBehaviour_OnDestroy(); } }

Also, I've recently encountered another issue in NetworkObject at line 518-ish where a NetworkObject in the RunTimeParentNetworkBehaviour can be null by the time the program is shut down. The following fix of adding an extra != null can fix it, as below:

        Observers.Clear();
        if (NetworkBehaviours.Count > 0)
        {
            NetworkBehaviour thisNb = NetworkBehaviours[0];
            if (RuntimeParentNetworkBehaviour != null)
            {
                if (RuntimeParentNetworkBehaviour.NetworkObject.RuntimeChildNetworkBehaviours != null)
                    RuntimeParentNetworkBehaviour.NetworkObject.RuntimeChildNetworkBehaviours.Remove(thisNb);
            }
        }

[FirstGearGames]

Appreciate it.

[edunad]

Having the null issue mentioned above, the null check fixes it

[FirstGearGames]

Yeah, it's not been marked as resolved yet but will be most likely next release.

…

On Wed, Dec 11, 2024, 3:19 PM FailCake ***@***.***> wrote: Having the same issue after updating to the latest fishnet version (pro 4.5.6) 41329265-4F05-4747-9604-3087A4628ED4.png (view on web) <https://github.com/user-attachments/assets/c0b5e795-2207-40a7-b764-41a6444f2744> — Reply to this email directly, view it on GitHub <#818 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGPJC3SUBA7SPHF3EJHNYOD2FCM5DAVCNFSM6AAAAABR76ZK2OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKMZXGAZTINRTGI> . You are receiving this because you commented.Message ID: ***@***.***>

[FirstGearGames]

I'm changing the detach check to this, which should only try to reattach if not shutting down the game or stopping play mode

                    if (_detach && !ApplicationState.IsQuitting())
                        _graphicalObject.SetParent(_rootTransform);

The runtimeparent one should already be fixed.
Please let me know if issue persist for the graphical one in 4.5.7 release.
If you're still getting the runtimeparent one as well, make a new issue.