Reproduction steps:
1. Create a new project
2. Create two GameObjects in the Scene
3. Select one of the GameObjects in the Hierarchy
4. Open Window > Sequencing > Timeline
5. Press the "Create" button in the Timeline window
6. In the Timeline window create an activation track
7. Assign other GameObject to the activation track
8. Move the "Active" part of the activation track further in Timeline
9. Open Edit > Undo History
10. Undo everything up to the creation of the second GameObject

Expected result: No warning message appears
Actual result: "SendMessage cannot be called during Awake, CheckConsistency, or OnValidate (Cube: OnMeshFilterChanged) UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)" appears in the Console

Reproduced with: 1.6.4 (2021.3.0f1), 1.7.1 (2022.1.0b16, 2022.2.0a10)
Could not test with: 2019.4.38f1, 2020.3.33f1 ("Undo History" not introduced)