Send to Unreal Blender Plugin - meshes are black after baking (missing 2nd Lightmap UV)

Using the new Send to Unreal plugin in Blender to automatically send meshes inot UE4.
Works great but after baking with Static Lights my meshes are always black.
After some searching I discovered the error is most likely my meshes are missing the 2nd UV index for Lightmaps.
In the Mesh Editor the Light Map Coordinate Index is stuck at 0 and cannot be changed to 1!

I’m no Blender guru. Is anyone else using this workflow and can suggest the easiest solution for Blender to automatically create the 2nd Lightmap UV on export?

Not sure if it’s the cause of the problem, but are the mesh channels (0-2) enabled for 0 and 1 in their details panels?