Whoops! It seems like you're trying to do something that you can't do on the Roll20 Development Server. Try your action on the main server instead.
Specifically, accounts are created, updated, and managed (including password resets) on the main server, and then all account information is synced to the Development server every few hours. So if you've updated or reset your password on the main server, or just signed up as a Pro, it may take a little bit for that informaiton to get synced to the Development server.
As always, if you have any questions, please don't hesitate to ask in the forums (please keep all Development Server-related bug reports, suggestions, and questions in the Pro-only sub-forum.)