Hey, that's because your username exists in the Revive Launcher, but not in FH2. Have you tried creating a new account? To do so:
1) Open up FH2 Launcher and selection "options"
2) On the gameplay tab, login as "<none/Manage accounts>"
3) From there, you should be brought to the main menu, click "manage accounts", and lastly, "create account".
Best regards,
Roughbeak