Steps to reproduce:

1. Open attached project "785775.zip"
2. Open scene "BootScene"
3. In hierarchy, notice "wand_gateway" object
4. Expand "wand_gateway" and then expand its child "Bonuses" game object
5. Notice a large number of child game objects
6. Re-select "wand_gateway" and delete it
Unity crashes

Note: Sometimes error "Failed to create Object Undo, because the action is too large. Clearing undo buffer" is printed instead of the crash

Workaround: Delete objects in smaller chunks

Not reproducible: 5.1.4f1 - Error about failing to create Object Undo is always printed
Reproducible: 5.2.4f1, 5.3.4p2, 5.4.0b13 - Unity crashes but occasionally previously mentioned error is printed