Unexpected MonoBehaviour.Awake() calls when stopping Play mode after loading scene with activateOnLoad=false

Unity Engine
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I’ve encountered what appears to be unexpected behavior in Unity when working with Addressables to load scenes asynchronously.

Steps to reproduce:

  1. Create a project with Addressables package
  2. Create a test scene (e.g., “example.unity”) with some GameObjects containing MonoBehaviours
  3. Add the scene to Addressables
  4. In your main scene, load the test scene asynchronously with activateOnLoad = false:
var handle = Addressables.LoadSceneAsync("example.unity", LoadSceneMode.Additive, false);
var sceneInstance = await handle.Task;
  1. Stop Play mode in the Unity Editor before calling sceneInstance.ActivateAsync()

Expected behavior:

Since the scene was loaded with activateOnLoad = false and was never activated before stopping Play mode, the Awake() methods of MonoBehaviours in that scene should not be called.

Actual behavior:

The Awake() methods of MonoBehaviours in the loaded but not activated scene are being called during editor Play mode shutdown.

Additional observations:

  • The Application.quitting and Application.unloading events are not triggered at the time these unexpected Awake() calls happen

  • This creates a situation where I cannot properly handle exceptions or prepare for this early initialization

  • The behavior is problematic because objects may try to access dependencies or systems that are already being torn down as part of the Play mode exit process

Unity version:

60000.0.41

Question:

Is this the intended behavior? If so, how should developers handle this situation to prevent errors when MonoBehaviours in non-activated scenes attempt to initialize during Play mode shutdown?

As a result, this situation can cause crashes when stopping Play mode in the editor.

Additionally, in this situation, the Awake calls occur before both Application.quitting and Application.unloading events are triggered.