Veyon 4.10.3: Automatic reboot and logout loop at login screen on Master/Teacher PC

[dav.p12]

Hi everyone,

I am writing to report a critical issue we encountered on our school's teacher computer after updating Veyon. Attached you will find the link to the video in question showing the exact behavior.

Description of the issue:
Since installing version 4.10.3 on the Master (teacher) PC, the machine has become completely unusable due to a reboot and logout loop:

As soon as the computer boots up and reaches the Windows login screen, it reboots on its own after a few seconds.

If I manage to type the credentials quickly enough before it restarts, the system immediately kicks me out and displays the "Logging out..." screen.

Temporary Workaround:
To fix this, I had to boot the PC into Safe Mode, uninstall version 4.10.3, and downgrade to the previous version, 4.10.2. With version 4.10.2, everything works flawlessly again and no crashes or reboots occur.

I would like to know if this is a known bug in release 4.10.3 or if there is a specific incompatibility (maybe with the Veyon service driver or a recent Windows Update).

Has anyone else experienced this issue or found a solution?

Thank you in advance for your help!

Video login screen:

[tobydox]

This looks serious and does not happen here during testing. Can you share your Veyon configuration, if you like also via private message or e-mail?

[tobydox]

What also would help for debugging are the following steps:

A) before upgrading, change the VNC server backend to Headless VNC server - if the reboot does not happen after upgrading, the issue is related with the updated UltraVNC server component in Veyon 4.10.3
B) before upgrading, disable Veyon service autostart - login should work normally also after upgrading. What happens when starting the service manually after being logged in?
C) Check the Windows event log for indications about why the system has been rebooted
D) In Veyon Configurator in advanced view mode, at page "Windows" there's a setting called "Handling of interfering windows". Is it set to a value other than "None"? If so, please revert it to "None".

[dav.p12]

Unfortunately, due to my state contract, I cannot share configurations or other details for privacy reasons. However, I can say that it is the same one as always, which has never caused any issues. As soon as I can, I will install the new version to provide feedback.
I'm also convinced that the problem could be the dated PCs we have at school.
Thank you.

[dav.p12]

@tobydox If necessary, we will also use the debug mode. Thank you.