Install ukui-media-common by entering the following commands in the terminal:
sudo apt update sudo apt install ukui-media-common
Description:
UKUI media utilities (common files)
UKUI media utilities are the audio mixer and the volume control applet. . This package contains the common files.
Homepage: http://www.ukui.org/
Version: 1.1.2-0ubuntu1
Section: universe/x11