We had to pick up the key from another address. The woman gave us wrong instructions for the location.
When we finally found it, we understood, that we don't know the flat number and floor and started to call Claudia and the woman, who gave us the key. Noone answered. We sent a message to Claudia as well, but she didn't reply. The only one option for us was to search ourselves the apartment floor by floor, flat by flat, disturbing the neighbours in the evening. Fortunately the neighbours were very helpful. It took us more than a hour to find the flat. We felt terrible, tired and disappointed. The attitude of Claudia was incorrect. At 04:00 AM she sent us a message to ask, if we fond it. We woke up and couldn't sleep anymore. It was really terrible. In case that Airbnb needs more information, we will be helpful anytime.
The flat is nice, clean and very good located. It' s closed to the centre, museums, the opera, cafeterias, restaurants, metro station and supermarkets.