Last weekend, the online banking of Postbank was adapted to the new PSD 2 regulations (German): https://www.postbank.de/privatkunden/zwei-faktor-authentifizierung.html
Account data retrieval is currently not possible via Outbank. We are already working on full speed to solve the problem – no action is required from your sight right now.
Thank you very much for you understanding.
Detailed information about PSD2 can be found in our blogpost.