Invalid serial key

[Zzehth]

A friend today bought the game, and when he wants to join a server this message appears:  Invalid serial key, then he clicks again and another message appears asking him to insert a 4x4 key.. hes key is 4x6.

Any ideas to fix the problem?

[Hellomoto7]

it's probably steam running out of warband codes, I think it fixes itself in a day or two

if not, I think you can also e-mail taleworlds the key, and they'll give you a 4x4 one