**Step 1 -** Take a Timeshift snapshot just in case this goes horribly wrong and you need to revert
**Step 2 - Disable cinnamon-screensaver**
Run this command in a terminal. if you have multiple users you will need to do this for each user account.
gsettings set org.cinnamon.desktop.session idle-delay 0 && gsettings set org.cinnamon.desktop.screensaver idle-activation-enabled false && gsettings set org.cinnamon.desktop.screensaver lock-enabled false
**Step 3 - Install xscreensaver**
Run this command in a terminal.
apt install xscreensaver xscreensaver-data-extra xscreensaver-gl xscreensaver-gl-extra
**Step 4- Link the cinnamon-screensaver-command to xscreensaver-command**
Run this command in a terminal.
sudo ln -sf /usr/bin/xscreensaver-command /usr/bin/cinnamon-screensaver-command
Please note this link will be overwritten by any future updates to the cinnamon-screensaver package. Simply rerun this command after any update to cinnamon-screensaver,
**Step 5 - Set xscreensaver to start at user logon**
Open Startup Applications and add a custom startup entry with no delay to run the command xscreensaver if you have multiple users you will need to do this for each user account.
**Step 6 - Reboot**
**Step 7 - Set up your xscreensaver preferences**
In the menu xscreensaver properties can be found in the preferences category as a 2nd Screensaver entry with the description Change screensaver properties. Alternatively you can launch it from the terminal with the command xscreensaver-demo. Most of the settings are self-explanatory. Blank time is the idle time before the screensaver kicks in.
**Step 8 - Test**
If all has gone well your menu lock screen shortcut and Ctrl-Alt-L keyboard shortcut should lock the screen with the xscreensaver lock-screen. The screensaver should kick in after your specified idle time and if you have set it to lock after a time period in xscreensaver properties that should work too.
//Source: https://forums.linuxmint.com/viewtopic.php?f=42&t=284037//