I should to add my report another similar bug. I do "desktop behavior"->"Screen locking"-> ... do something...->all settings->SEGMENTATION FAULT (the window closes) I have 4 variants of wallpapers in "Screen locking": Hunyango, Plain Colour, Image, Slideshow. But I have SEGMENTATION FAULT (and closing window) only if I do something when my chosen wallpaper is Plain Colour, Image or Slideshow or I change wallpaper, but not when my chosen wallpaper is Hunyango.
When my chosen wallpaper isn't Hunyango, I have Segmentation fault often, but not always. Console uotput: chatrapati@Debian:~$ systemsettings5 Segmentation fault chatrapati@Debian :~$ And in /var/log/syslog I have: Dec 1 23:32:42 Debian kernel: [18997.209334] traps: systemsettings5[6181] general protection ip:7f7371a31d85 sp:7fff2ec05a60 error:0 in libQt5Qml.so.5.7.1[7f7371892000+3dd000] -- Павел Банщиков