XnView Software

I use the XnView one. I checked the xnview.sh too and it makes no difference.

Process 4446 (XnView) of user 1000 dumped core.

Stack trace of thread 4446:
#0 0x00007f5095bdcf15 _ZNK7QWindow5winIdEv (libQt5Gui.so.5)
#1 0x00007f507e49b5a5 n/a (KDEPlasmaPlatformTheme.so)
#2 0x00007f507e49bb6d n/a ...

Process 1457 (XnView) of user 1001 dumped core.

Stack trace of thread 1457:
#0 0x00007f53b9daff15 _ZNK7QWindow5winIdEv (libQt5Gui.so.5)
#1 0x00007f53a269b5a5 n/a (KDEPlasmaPlatformTheme.so)
#2 0x00007f53a269bb6d n/a (KDEPlasmaPlatformTheme.so)
#3 0x00007f53ba743c3d n/a (libQt5Widgets.so.5 ...

If you try to launch XnViewMP on KDE and have enabled the application menu shortcut on the titlebar, the application will instantly crash. This happens every time.
(The application menu icon is enabled at System settings -> Application style -> Window decorations -> Buttons.)