Hello @stevecook172001 @javedsher !
Sorry, I had my A-Level exams. 
My solution for the screensaver-problem is the following: (Never seen a workaround on the internet too 
)
I have a 64-Bit Fat-Client Setup. You should remove the relevant things for you.
First we have to enable ltsp-remote-apps:
Add to: /var/lib/tftpboot/ltsp/amd64/lts.conf on the server.
[Default]
LTSP_FATCLIENT = True
REMOTE_APPS = True
Install i3lock on the server:
sudo apt-get install i3lock
The Server is ready. Now we have to modify the client-image:
sudo ltsp-chroot -c -p
In the Image Chroot:
apt-get remove mate-screensaver
Create: /usr/share/applications/i3lock.desktop
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Exec=ltsp-remoteapps i3lock -n -c 000000
Name=Lock Screen
Comment=Locks screen with i3lock
Icon=mate-typing-monitor
Category=
Client modification done.
exit
sudo ltsp-update-image
If the clients get the new image, the mate-screensaver won’t run automatically. Instead the user can lock the screen via the i3lock entry created in his applicationsmenu. I’ve choosen i3lock, because it will be executed on the server (ltsp-remote-apps) and it is very resource-friedly.
I don’t need automatic activation of the screensaver in my setup, if you do so, you should try to add this to the client image:
apt-get install xprintidle
And as a startup script: (not tested)
#!/bin/bash
idletime=$((1000*60*60)) # 1 hour in milliseconds
while true; do
idle=`xprintidle`
echo $idle
if (( $idle > $idletime )); then
#sudo shutdown -P now
ltsp-remoteapps i3lock -n -c 000000
fi
sleep 1
done
The main point here is, that when it is run on the server, we don’t get the authenticatoin-issues like running natively on the client-image.
I hope I helped you,
Matthias
