Kernrechtsfrage
Whether the federal appeal had to be entered into despite non-payment of the required advance on costs within the extended time limit.
Extrahierter Entscheid
No. Because the advance was neither paid nor duly proved within the extended deadline, the appeal could not be heard.
Extrahierte Begründung
The appellant failed to provide the cost advance even after being granted a grace period and also failed to prove timely payment; under the Federal Supreme Court Act, the consequence is non-entry.