Can connect but get only a blue screen

[dasmensch]

Hello,

After playing with installing Veyon off and on the last week I finally got it sort of working. The master connects to both the other computers, I can send a message, open a browser, force a reboot, demo, etc... BUT I cannot see the screen. I just get a blue screen when I try to remote control. I have switched from wayland to X11 on all 3 computers. One thing to note, if I use Builtin VNC server (x11vnc) for the VNC server plugin I cannot connect. I have to use the Headless VNC server to establish a connection.

I have an Ubuntu 22.04.3 running the master and 2 Edubuntu 23.04. The Edubuntu computers are running Veyon 4.7.5 as even adding the PPA it will only pull that down. The Ubuntu machine is running 4.8.2. I installed all the pre-reqs except libprocps-dev was not able to be installed on the Edubuntu machines "Unable to locate." I've searched around but didn't see any postings with a blue screen. Best guess is something with my X11 setup on one or all machines. Hopefully someone has seen this before and it's an easy fix.

Ubuntu:
Veyon: 4.8.2 (Aug 14 2023)
Qt: 5.15.3 (built against 5.15.3/x86_64-little_endian-lp64)
OpenSSL: OpenSSL 3.0.2 15 Mar 2022

Edubuntu:
Veyon: 4.7.5 (Feb 3 2023)
Qt: 5.15.8 (built against 5.15.8/x86_64-little_endian-lp64)
OpenSSL: OpenSSL 3.0.8 7 Feb 2023

[tobydox]

The headless VNC plugin will always shot a blue screen only. You have to use the x11vnc backend. If you switched from Wayland to X11, it should work. If not, what errors can you see in the VeyonServer log files?