How to reproduce:
1. Open the "Undo_Crash.zip" project
2. Open the "SampleScene.unity" scene
3. Select "Bullet" game object in the Hierarchy.
4. Change some values in the "Hit Box Component" script
5. Undo the changes (CTRL-Z)
6. If Unity didn't crash, repeat 4-5

Actual result: Unity crashes.

Reproducible with: 2019.1.0a12, 2018.3.0f1, 2018.3.0a10.

Notes:
Can't test 2018.3.0a9 and below because of script/prefab errors.