Demo still doesn't work.
I brought the whole lab up to 126.96.36.199
It went to Demo, showed my screen for a few second on a couple of the 7 students logged in a lab of 26 clients. Then, Demo stopped working even on the couple that did get my screen.
I was able to back out of Demo mode with out crashing their computer.
i have the same problem .. i opened a new topic: https://veyon.nodebb.com/topic/1258/veyon-4-5-4-vnc-serveur-crash-on-demo-mode
where I put the logs to see if tobydox manages to understand what is wrong ...