Have you actually paid for a monthly subscription yet? 1.0 players only got 15 days free from the start of 2.0 (and then an additional 7 days added later) and our free time ran out nearly two weeks ago. If you don't currently have an active subscription you won't be able to play.

When you load the game for the first time you should be able to say "I already have an account" and just point it to your existing SE account details with the 1.0 account on it. As long as that account has a valid subscription you'll be able to play. If it doesn't have a valid subscription, I guess that's why you're getting asked for the code.

You can log into the Mog Station to apply a subscription at https://secure.square-enix.com/accou...est=mogstation