Install gconf-service-backend by entering the following commands in the terminal:
sudo apt update sudo apt install gconf-service-backend
Description:
GNOME configuration database system (D-Bus service)
GConf is a configuration database system for storing application preferences. It supports default or mandatory settings set by the administrator, and changes to the database are instantly applied to all running applications. It is written for the GNOME desktop but doesn't require it. . This package contains the D-Bus enabled daemon that is used internally by the GConf library to access configuration data. It is an internal implementation of gconf used to work around multiarch-related upgrade problems, and will eventually be merged back into gconf-service.
Homepage: http://projects.gnome.org/gconf/
Version: 3.2.6-4ubuntu1
Section: universe/libs