The option to assign a Shadow Physics Asset is located in the Destructibles Details panel even though they are only supported for Skeletal Meshes currently. This assigned shadow physics asset cannot be enabled since the options do not exist in the placed instance in the level.
1. Create a Destructible Mesh
2. Open the Destructible in the Destructible Mesh Editor
3. In the Details on the right, scroll down to Lighting and locate Shadow Physics Asset
Regression: No
Results: Shadow Physics Asset shows up in the Destructibles Details panel/
Expected: Shadow Physics Asset shoudl not be visible in the Destructibles Details Panel
Head over to the existing Questions & Answers thread and let us know what's up.