"Unsupported type EventReference" error when saving prefabs with Timeline in Unity Editor

Unity
1

I’m encountering an editor-only console error when viewing and saving prefabs that contain Unity Timeline tracks with FMOD event playables:

Unsupported type EventReference
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler ()

Environment:

  • Unity Version: 6000.2.10f1

  • FMOD Unity Integration Version: 2.03.09

  • Platform: macOS

When it occurs:
The error appears specifically when:

  1. Opening a prefab in the Unity Editor that contains Timeline tracks

  2. Saving changes to these prefabs

  3. The Timeline contains FMODEventPlayable assets

Technical details:
The error seems to occur when Unity’s serialization system encounters the EventReference struct. The struct is properly marked with [Serializable] and works correctly at runtime, but Unity’s Timeline serialization path appears to have issues with the custom type.

Looking at the code, EventReference is used in:

  • FMODEventPlayable.EventReference (line 27 of FMODEventPlayable.cs)

  • FMODEventPlayableBehavior.EventReference (line 189 of FMODEventPlayable.cs)

Impact:

  • This appears to be an editor-only warning

  • Audio events seem to function correctly at runtime

  • Prefab changes are saved successfully

  • No actual functionality appears to be broken

Question:
Is this a known issue with Unity’s Timeline system and the EventReference type? Is there a recommended workaround or will this be addressed in a future FMOD integration update?

2

This is a Unity serialization bug.