Opacity Map is exported from Max using Datasmith but not Imported

Import Max scene attached in Unreal .

In Material folder 

Open material instance

In the detail pane , general setting , enable double sided

Notice that in the texture parameter group 

Diffuse and texture seems to have a texture but the display shows black.

Double click on the texture , hit re import and the chain texture will appear.

 

Should now be visible in the viewer.

 

Not to sure why the opacity map get disconnected or dropped.