Key legal question
Whether the appeal could proceed despite non-payment of the required advance on costs after the grace period.
Extracted holding
No. Because the advance was not paid within the extended deadline, the appeal could not be heard.
Extracted reasoning
Under Art. 62(3) BGG, failure to pay the advance within the set time limit permits non-entry in the simplified procedure under Art. 108(1)(a) and (2) BGG.