Hi again, I just upgraded a second system to trixie, and in this one "Configure oKular" is working as intended. The differences between the two systems I am aware of are :
1) The first one, the one where "Configure oKular" crashes okular (let's call it system A), had Debian originally installed around 24 years ago as a Debian woody and both software and hardware have been kep updated/upgraded since then. The system where "Configure oKular" works (let's call it system B) started as bookworm around two years ago. 2) Base packages are the same for both systems, but there are lots of packages accumulated over time in system A which are not in system B. I think all packages in system B are also in system A. 3) Curiously enough, upgrade to trixie in system A worked flawlessly while in system B I had to reinstall manually some KDE packages (kmail), which were removed for some reason during the upgrade. Regards, Josep Guerrero