This error comes from your 3ds Max Scene, every object needs 2 UV unwraps, one in channel 1 for texture maps and one in channel 2 for lightmap, if you´re missing one of the, you may receive this error, 

To solve this error, you must execute the UNWRAP command from our script, you can unwrap channel 1 or/and channel 2 , if the script is not working and it does not make the unwrap, you will need to check your name convention on the objects

After this, you should be able to import successfully