Install baloo4 by entering the following commands in the terminal:
sudo apt update sudo apt install baloo4
Description:
framework for searching and managing metadata.
A framework for searching and managing metadata in KDE. . This package contains the kdelibs4 version of the binaries, it can also be replaced with baloo-kf5.
Homepage: http://projects.kde.org/baloo
Version: 4:4.14.3-0ubuntu6
Section: universe/kde