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.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-66369 in the post.