Invalid Registration

I am trying to help a friend that purchased the game through steam. He has a free trial account but no luck with getting the game registered. I have seen things that talk about wrong region, but it doesnt give him that error. It just says invalid registration key. Is there a trick to it that I dont know that I could pass on to him? Is Steam just giving him a bad code?

Did he make a Square Enix account on their website? When i made a new toon i had to create an account and register the codes and everything there then i was able to create a character.