Install overlay-scrollbar by entering the following commands in the terminal:
sudo apt update sudo apt install overlay-scrollbar
Description:
Scrollbar overlay - configuration
Overlay scrollbar is a GtkModule enabling a dynamic overlay behavior. . This package contains GSettings schemas and startup scripts for overlay scrollbars.
Homepage: http://launchpad.net/ayatana-scrollbar
Version: 0.2.17.1+16.04.20151117-0ubuntu2
Section: universe/libs