If your NFSW account existed prior to Aeria, converting AP to SB -> WILL NEVER WORK.
Accounts have to be in sync, which isn't the case if the EA account exists prior to Aeria.
To use AP in NFSW:
- The Aeria Account has to have registered before NFSW.
- You have to register NFSW over Aeria, with the same Email-address.
- If that address is already registered at EA, it won't work.
Just change the Mail-adress for Aeria to another one and after it succeeded, register a new EA (in fact NFSW) account by clicking a link over Aeria's NFSW page (should say "register" or "Play Now" or something).
After you input your mail and PW, the Aeria and EA Account is connected and you can use AP.
I had the same trouble, so I keep this Account as a spare to submit helpful advices..
I am also in the german EA Forums, helping with technical problems.