Question juridique clé
Whether the subsidiary constitutional complaint could proceed despite failure to pay the court cost advance within the final deadline.
Solution extraite
No. Because the appellant neither paid the advance nor proved timely payment, the complaint had to be declared inadmissible.
Motifs extraits
After an unextended grace period under Art. 62(3) BGG and explicit warning of non-entry, the missing advance payment triggered non-entry under Art. 117 BGG in conjunction with Art. 108(1)(a) BGG.