Welcome to the website and I hope you enjoy it because there is a lot of it to look over and learn about. I encourage you to use the forum's search tools to help you with your questions because there is a very, very good chance that that problem has come up before.
As I said this question has been asked and daflyboys, who is the roster demigod around here recommends for people to DELETE their current roster (in your case the 2013 one) and then put in its place the new roster. Try that and you'll have some good results. Don't thank me, I'm just paraphrasing the Master.