Changing LOD materials on Merged Actors Crashes Editor

If you merg actors with LODs with the setting LODSelection Type set to "Use all LOD levels" then apply a material to the element 0 assigned to LOD1 the engine will crash.

NOTE
I wasn't able to repro this crash when the merged assets already had materials applied to all of their LODs in the static mesh editor before the merging process.

1. Open attached project
2. Open the asset "SM_MERGED_LODtest2"
3. In the static mesh editor assign the material named "Grey" to LOD1 Element 0

ALTERNATE REPRO with merging process included

1. Open attached project
2. Open a new default map
3. Drag 2 "LODtest" assets into scene from content browser side by side
4. Open the merge actors tool with the 2 assets selected
5. Make sure LODSelection Type is set to "Use all LOD levels"
6. Merge actors
7. Save the merged actor
8. Open the actor you just saved in the content brower
9. While in the static mesh editor apply the material named "Grey" to LOD1 Element 0

RESULT
Crash
EXPECTED
The material is assigned to LOD1 for all merged assets.