Install kwin-data by entering the following commands in the terminal:
sudo apt update sudo apt install kwin-data
Description:
KDE window manager data files
KWin (pronounced as one syllable "kwin") is the window manager for the KDE Plasma Desktop. It gives you complete control over your windows, making sure they're not in the way but aid you in your task. It paints the window decoration, the bar on top of every window with (configurable) buttons like close, maximize and minimize. It also handles placing of windows and switching between them. . This package contains the data files
Homepage: https://projects.kde.org/projects/kde/workspace/kwin
Version: 4:5.12.4-0ubuntu2
Section: universe/libs