Created attachment 108103 [details]
systemsettings5-20170930-181806.kcrash.txt

I've tried plasma 5.10.95 on a gentoo system with debug information. It was worse than plasma-5.10. My computer is a notebook with an 4k screen, to fix the scaling I force the font to 192dpi.
Compared to the previos version and a X11 session, something was obvios wrong everything was huge, like 2-4 time larger than it should be. After opening the systemsetting to see if there is something wrong, the fist thing I saw was that the widgets where not fitting into the window (some flickering outside). I resized the window to stop that. It crashed after activating font or the diplay config/tab. The backtrace looks more like it was the font dialog. (I think I've change from diplay to font)