Steps to repro:
1. Launch the attached project / create a new project
2. Create 2 scenes
3. Copy a game object from any scene and deselect any selection to choose the active scene
4. Paste the GO (SUCCESS)
5. Now perform an undo operation

Note that Unity crashes.

The stack trace is:
#0 0x000001019c3f1f in ClearTransformParentUndo(Transform&, UnityScene&, std::string const&)
#1 0x000001019c41ec in UndoTransformParent::Restore(bool)
#2 0x000001019c27dd in UndoManager::Apply(std::list<UndoBase*, std::allocator<UndoBase*> >&, bool)
#3 0x000001019c2b01 in UndoManager::Undo()
#4 0x007fff8f192cd7 in _os_activity_initiate
#5 0x007fff8dffaeb1 in -[NSApplication sendAction:to:from:]