Unity Issue Tracker - Undo does not work when GameObject is replaced with Prefab instance by holding Alt and dragging the Prefab
Fixed
UUM-2264
Undo does not work when GameObject is replaced with Prefab instance by holding Alt and dragging the Prefab
Unity: Scene Management
Fixed
2023.1.X
2022.2.X
Fix that Undo does not work when GameObject is replaced with Prefab instance by holding Alt and dragging the Prefab, also the scene was not marked dirty. The modifier key has changed from Ctrl on Windows and Linux and Cmd on OSX.
Reproduction steps:
1. Open the attached project ("AltDragBug.zip")
2. Open "SampleScene" Scene
3. While holding Alt (option on Mac), drag the Sphere Prefab from the Project window onto the Cube GameObject in the Hierarchy window
4. Observe the "SampleScene" Scene in the Hierarchy window
5. Save the project
6. Close and reopen the project
Expected result: The Scene is marked as dirty (step 4) and the changes are saved and remain after reopening and undo works
Actual result: The Scene is not marked as dirty and no changes are saved