Install unity-schemas by entering the following commands in the terminal:
sudo apt update sudo apt install unity-schemas
Description:
Interface designed for efficiency of space and interaction.
Unity is a desktop experience that sings. Designed by Canonical and the Ayatana community, Unity is all about the combination of familiarity and the future. We bring together visual design, analysis of user experience testing, modern graphics technologies and a deep understanding of the free software landscape to produce what we hope will be the lightest, most elegant and most delightful way to use your PC. . This package contains the configuration schemas used by unity.
Homepage: https://launchpad.net/unity
Version: 7.5.0+18.04.20180413-0ubuntu1
Section: universe/gnome