Install cinnamon-screensaver by entering the following commands in the terminal:
sudo apt update sudo apt install cinnamon-screensaver
Description:
Cinnamon screen saver and locker
cinnamon-screensaver is a screen saver and locker that aims to have simple, sane and secure defaults, and be well integrated with the Cinnamon desktop.
Homepage: http://cinnamon.linuxmint.com/
Version: 3.6.1-2
Section: universe/x11