Unity 6.1 Object initialized twice without reset error

[gregharding]

General
Unity version: 6.1.1f1
Fish-Networking version: 4.5.7, 4.5.8
Discord link: https://discord.com/channels/424284635074134018/1034477094731784302/1369560923051790458

Description
When a server/host starts, stops and then restarts in the same scene, all scene NetworkObjects throw an error Object was initialized twice without being reset. Object Name [xxx] Id [nn].

Unity 6.1.1 shows the issue.
Unity 6.0.30, Unity 6.0.48 do not have the issue.

Replication
Steps to reproduce the behaviour:

1. Create a test scene with the standard FishNet NetworkManager.
2. Create a gameobject with a NetworkObject, ie. a scene NetworkObject.
3. Play the scene.
4. Using the standard FishNet UI, start the server, stop the server, and start the server again.
5. See the error.

Expected behaviour
NetworkObjects should be reset so they can initialise without error.

[FirstGearGames]

You'll have to be on the latest version given these errors were fixed along the 4.6 releases.

[gregharding]

We are testing upgrading FishNet 4.5.7 -> FishNet 4.6.7 hf0 and the issue still occurs in some circumstances.

There appears to be an event flow change in FishNet 4.6 with scene objects (scene NetworkObjects) that are inactive when the server starts now receive events like OnStartServer/OnStopServer, eg. they are under a plain inactive holder gameobject. This exposes start/teardown races with our current 4.5.x code which assumes that NetworkBehaviours that receive OnStartServer have previously run Awake and OnEnable and are effectively wired up ready to go. In 4.6 there's no guarantee during Awake or OnStartServer that the other method has ever been called which means there's a bunch of housekeeping for initialisation/teardown lifecycle to know the exact state of the NetworkBehaviour at any point. (Is there a way to disable this lifecycle behaviour in FishNet 4.6? It's a big blocker for us upgrading from FishNet 4.5.)

The original initialisation error still occurs in FishNet 4.6 if you have a plain inactive holder gameobject with a NetworkObject nested underneath it. If you start, stop, and start the server the issue still occurs.

[gregharding]

I tested Unity 6.0 FishNet 4.6.7 hf0 with this patch from Discord (https://discord.com/channels/424284635074134018/1034477094731784302/1370192828486914188) and both issues were resolve. The nested networkobjects under the plain inactive gameobject did not receive unexpected OnStartServer() network events as they were not Awake, and no scene networkobjects have any issues trying to initalise twice when the server is repeatedly start/stop/start again. So, both issues were fixed.

I also tested FishNetworking.4.6.7R_exp01. The nested networkobjects under the plain inactive gameobject did not receive unexpected OnStartServer() network events as they were not Awake. However, scene networkobjects did throw the initialise twice error when start/stop/start the server repeatedly, so this version only fixes one issue.

Steps to reproduce the issue in 4.6.7 hf0;

• Create a test scene with the standard FishNet NetworkManager.
• Add an empty gameobject 'holder' to the scene.
• Add two new gameobjects with a NetworkBehaviour that Debug.Logs inside Awake() and OnStartServer().
• Leave one networkobject at the scene root - it's a normal scene object.
• Move the second networkobject to be a child of 'holder'.
• Deactivate the empty gameobject 'holder'. The child networkobject is intended to never Awake or receive OnStartServer().
• Play the scene.
• Using the standard FishNet UI, start the server, stop the server, and start the server again.
• See the errors. The child object receives OnStartServer events as if it was active, but it has never received Awake/OnEnable. Some versions of Unity/FishNet also try to initialise the networkobjects twice.

[FirstGearGames]

Resolved in 4.6.8