GPU Lightmass Error

i used datasmith to export my Model from 3DS Max into Unreal Engine but when i try Making Gpu Lightmass Build ( Luoshang GPU lightmass ) i get this Error,

After removing lots of Models it worked so i went to check UV Channels of all Models i deleted found that they already have 2 Channels 0,1 and the Assigned Lightmap Channel is Correct as well So i have 2 Questions Here :-

1 - How to Fix that !?

2 - How to know that this Model wont cause Problems / Errors when Building Lighting !!? what else should i check rather than UV Channels !?

Thanks Alot