On Ubuntu distro, if you see the error message in console as the following
whenever you run a Gnome-based applications, chances are you had ‘overlay-scrollbar’ package previously installed but now removed. However, the configuration file which came with that package remained on your system.
We can verify this with this command:
rc : remove but config file still presents.
On my Ubuntu desktop, this config file resides at /etc/X11/Xsession.d/81overlay-scrollbar.
To correct this problem, we can purge ‘overlay-scrollbar’ package with this command:
You would need to log out and log back in of your current X session (KDE, or Gnome) for the change to take effect.