Hi!
I have a problem with an object imported from 3ds Max, in this case a retro portable radio.
As you can see in the screenshot above, I have a beige plane (material, not color) inside an object with a transparent plastic material.
When I import it to Unity, the beige plane doesn’t show. The rest does, so basically it just red (the transparent object is showing).
Any idea what I might have done wrong?
You probably need to set the material of the transparent glass to use a transparent shader. By default I think unity just shades all imported materials with default - diffuse. I am not exactly sure how the imported object is configured in the inspector so I can’t say much more.
I figured it out myself, but thanks for the answers 
The problem persisted even with 2-sided material. What I did was simply turn the beige plane around 180 degrees.
Then it showed in Unity.