Kernrechtsfrage
Whether the appeal could be entered into despite non-payment of the court advance within the final deadline.
Extrahierter Entscheid
No. The advance was not paid within the non-extendable grace period, so the appeal was inadmissible.
Extrahierte Begründung
The appellant had long known of the advance-payment duty and had been granted extensions. No special unforeseeable grounds justified a further extension; under the Federal Supreme Court Act, failure to pay the advance leads to inadmissibility.