For KF5-based builds this is resolved because the improved heuristic for detecting light high-contrast themes (like "Desert") is used for VSD 3.3 and Gpg4win 4.4.

Ok, it was a missing update (although windows claimed to be up-to-date).
After installing 2025-06 [...] KB5060829 the Microsoft Print to PDF feature is available again and printing also works in Kleopatra/Okular.

It's also the same error in Okular, when a pdf is printed.

Same on gpg4win-4.4.1 @ win11 (here a bit more debugview context)

3	3.503991	8584	kleopatra.exe	org.kde.pim.kleopatra: Paperkey export finished:  0 status:  QProcess::NormalExit
4	3.691599	8584	kleopatra.exe	QPrintDialog: Cannot be used on non-native printers
5	3.691981	8584	kleopatra.exe	QPrintDialog: Cannot be used on non-native printers
6	3.692752	8584	kleopatra.exe	org.kde.pim.kleopatra: Printing aborted.

Works fine here.

I guess, that's ok then, moving this to done.

In T7594#202471, @timegrid wrote:

Shouldn't the enabled close button in win10 / disabled text / nr2 have green color? (it's the "search certs on server" dialog).

Shouldn't the enabled close button in win10 / disabled text / nr2 have green color? (it's the "search certs on server" dialog).

This also happens on Linux. And even with the Fusion style.

Thanks for the Windows 11 screen shots.

Thanks for the feedback. The issues are the same as on win10: