This won't always happen, but the call in ImportDestructibleMeshFromApexDestructibleAsset to LODModel.ReleaseResources(); will enqueue render commands to release the resource, but the call after that loop to ImportedResource->LODModels.Empty(1); will run destructors on the objects, which will fail if the renderer hasn't freed the resources yet.
Need to flush rendering commands before emptying the array.
1) Import a destructible mesh from an APEX asset (.apx, .apb)
2) Reimport the mesh
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-40911 in the post.