Repro steps:
1. Add a cube to the scene
2. Drag the cube to the project folder to create a prefab out of it
3. Open the SDF Baker and assign the prefab to it
4. Save the SDF settings to a file
5. Browse for SDF settings and switch between None and the new saved settings.
6. Unity crashes

Notes:
- Doesn't seem to happen with Mesh or setting files without any prefab/mesh assignments