[solved] fonts preview broken

I cannot preview any fonts in Netrunner 17? In dolphin the fonts are just black squares and in systemsettings - resp. kcmshell5 fontinst and kfontview - also no preview is shown (all white), see attached screenshot.

It’s independent from font and PC (tested on two systems with Netrunner 17), no matter if personal or system fonts. I also tried with dolphin and kfontview in root-mode.

Is something missing? How can this be solved?

Looks like a rendering issue. At least in the Font management window.
Did you maximized that window and clicked on other fonts to see if it reappears again ?

Can you turn off desktop effects with Alt+Shift+F12 and restart the font management app to see if it solves the problem ?

Maximize doesn’t change anything, it happens with every font and turning coompositing off also does not change anything (see attached screenshot without desktop effects).

Solved by updating libkfontinst5 and libkfontinstui5 to version 5.5.4.

I did a dist-upgrade and as backports are activated I thought that would pull in the backports version but it does not? I have to explicitly install package=version to get the packages from ppa.launchpad.net/kubuntu-ppa/backports/ubuntu?

Interesting. They might be hold back by some depending packages. I will test that here and try to reproduce.
Nice that you found a solution that might help others aswell.