SUMMARY Tried to change lock screen appearance (last action was click on the background color picker). System settings window closed (without crash notification). Subsequent attempts to launch "System settings" failed. STEPS TO REPRODUCE 1. Do something what systemsettings5 apparently can't handle in the tab "Desktop Behavior > Screen locking > Appearance". 2. "System settings" window closes by itself 3. Try to launch "System settings" again from launcher. 4. "$ systemsettings5" 5. "$ systemsettings5 --version" OBSERVED RESULT What seems like a crash on step #2 System settings does not launch on step #3 On step #4: > Please instantiate the QApplication object first On step #5: > Please instantiate the QApplication object first and no output about the version EXPECTED RESULT "System settings" application does not crash after step #1 "System settings" application launches on steps #3 and #4. Version info is printed on step #5. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 18.10 (available in About System) KDE Plasma Version: 5.13.5 KDE Frameworks Version: 5.50.0 Qt Version: 5.11.1
Please attach a backtrack of the crash. Thanks! For more details, see https://community.kde.org/Get_Involved/Bug_Reporting#Crash_reports_must_include_backtraces
I'm sorry if I didn't make myself clear in the bug report. This crash was not caught by crash assistant (like Kdenlive crash in my other bug report https://bugs.kde.org/show_bug.cgi?id=407844). Therefore, there is no backtrace that I could provide.
In that case you will need to generate it yourself. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
Because steps are not reliable, I can not longer reproduce.