As a supplement to the accusation that I was/am naive. It was my first apartment, I was young and many things were unknown to me, the notary, or the bank. The apartment was cheap, with the unpaid amount even cheaper, and there have been no problems so far. They only come up now during the sale. Another owner had to sue the developer's bank immediately back then because his bank wanted the first position in the land register. However, he paid the full purchase price, and it took time and cost money.