So Fighter (who is awesome) troubleshoots this issue with someone in this answers (and then in the link on the forums) here: https://answers.unrealengine.com/questions/71031/why-are-imported-models-appearing-black-after-the.html
It seems that this is pretty common and involves lighting setups primarily, though the solution was the creation of a second UV channel. I would follow along and sort of try Fighter’s ideas 1 by 1 until something works and something is bound to since he’s A+.