Q: Why can't I create an Apple ID?

iPhone 4s. It was my wife's but she upgraded to a 5c. I created an Apple ID for my 11 year old using the Family Sharing with no problems. He now has an ID and is receiving emails. I did a factory reset, clearing all Safari data. Now I try to sign in on the 4s at start-up and it keeps giving me the error 'can't create apple id.'

What can I do?

Thanks!

Dave