Created attachment 127502 [details]
Firefox without Gtk theme

SUMMARY

Once or twice a week the content of $HOME/.config/gtk-3.0/settings.ini file gets lost.  The file itself continues to exist, but becomes an empty, zero-sized (0B) file.   It happens randomly and apparently without a valid reason. 

As a result, Gtk apps (like Firefox, Thunderbird, LibreOffice suite) are opened as un-themed windows, with tiny, nano-sized interface fonts.


STEPS TO REPRODUCE

1. Empty existing $HOME/.config/gtk-3.0/settings.ini file:

$ > $HOME/.config/gtk-3.0/settings.ini

2. Launch Firefox

3. Observe Firefox window theme and decorations


OBSERVED RESULT

See attached "Firefox without Gtk theme" image.


EXPECTED RESULT

Currently cannot attach a second screenshot with normally themed Firefox window.


SOFTWARE/OS VERSIONS

Windows: <void>
macOS: <void>
Linux/KDE Plasma: Solus Kde Plasma
(available in About System)
KDE Plasma Version: 5.18.3
KDE Frameworks Version: 5.68.0
Qt Version: 5.13.2


ADDITIONAL INFORMATION

The content of $HOME/.config/gtk-3.0/settings.ini does not get lost in Arch Linux and Void Linux.  But the issue may be reproduced as described above.

Both Arch and Void are at higher software versions:

 - KDE Plasma Version: 5.18.4
 - KDE Frameworks Version: 5.69.0
 - Qt Version: 5.14.2