How to reproduce:
1. Create a new project
2. Create a “Canvas” GameObject
3. Add a “Button - TextMeshPro” GameObject as a child of the “Canvas” GameObject
4. Duplicate “Button - TextMeshPro” GameObject so there will be 1000 GameObjects
5. Drag “Canvas” GameObject to the Project window to create a prefab
6. Open the created “Canvas” prefab
7. In the Hierarchy tab, select any “Button” GameObject
8. In the Scene window, uncheck the “Auto Save” option (it is located in right top corner of the window)
9. In the Inspector, hide the selected “Button” GameObject
10. In the Scene window, click on “Save” button (it is located in right top corner of the window)
11. Observe the Console window
Actual result: “The EndLayoutGroup: BeginLayoutGroup must be called first” error is shown in the Console window
Expected result: No errors are shown in the Console window
Reproducible with: 2022.1.0a5, 6000.0.64f1, 6000.3.0a1
Not reproducible with: 6000.3.2f1, 6000.4.0b1, 6000.5.0a3
Fixed in: 6000.3.0a2
Reproducible on: macOS 15.3.2 (24D81) (M1 Max)
Not reproducible on: Windows 11 (Tested by CQA)
Note: The user reported getting other errors as well, however, CQA was unable to reproduce them. Further details are in the internal notes