It is important to input the data in the correct order. This means that you have to enter first the city/town, the street name and the postal code. Then the system will automatically suggest an existing address with the help of Google. Select this address and only then enter e.g. the number of your flat and/or “Stiege” (building unit). If you enter your flat number before this, Google may not be able to recognise your address and, thus, will not suggest one, resulting in a system error.