Created attachment 156103 [details] Visual Bug screenshot. SUMMARY *** Unable to use KDE System Settings. Most settings are non functional. Most menu are not properly visible. *** STEPS TO REPRODUCE 1. Start KDE System Settings. 2. Open menu like "About the System", "Audio", "User Feedback" 3. Visual problems can be seen. 4. Also unable to use many settings within KDE System Settings like "Appearance" menu. SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: 5.102.0 Qt Version: ADDITIONAL INFORMATION
Are you using Gnome?
(In reply to Nicolas Fella from comment #1) > Are you using Gnome? yup
The screenshot shows that your theming is broken. This means one of two things is happening (or possibly both): 1. You're using qt5ct, which overrides the theming set by Plasma. Solution: remove it 2. You don't have the qqc2-desktop-style framework installed, so your QtQuick apps are falling back to the built-in Qt Material style. Solution: install it and then tell your distro to pre-install it by default