Install gconf-service by entering the following commands in the terminal:
sudo apt update sudo apt install gconf-service
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 provides the D-Bus enabled daemon that is used internally by the GConf library to access configuration data.
Homepage: http://projects.gnome.org/gconf/
Version: 3.2.6-4ubuntu1
Section: universe/libs