@Luigi-Capp I have fixed it with the command "sudo apt-get -f install /home/luigicapp/Scaricati/Temp/veyon_4.7.5.0-ubuntu.jammy_amd64.deb" Luigi Cappellazzo

Are you using the latest version on both teacher and student computers?

A typical mistake is that Veyon add-ons are not installed on student computers. Also make sure to configure the Internet access blocking mechanism client-side. Is the Windows Firewall enabled on student computers? If not, please enable it and don't set any group policy which prevents applications from changing the firewall configuration.

This can be easily done with PSTools from Microsoft and a batch script or PowerShell. I use the following to manually remotely install veyon and the security keys when the GPO installer doesn't work for any reason. You can replace line 1 with a call to a list of computers rather than specifying a single computer if that fits your needs better. SET /p computer="enter computername:" XCOPY "\\networklocation\veyon-4.7.5.0-win64-setup.exe" "\\%computer%\C$\" /e /h /y XCOPY "\\networklocation\UserConfig.json" "\\%computer%\C$\" /e /h /y XCOPY "\\networklocation\veyon\Veyon\*.*" "\\%computer%\C$\ProgramData\Veyon\" /e /h /y timeout /t 5 CD "C:\PSTools\" psexec64 \\%computer% C:\veyon-4.7.5.0-win64-setup.exe /S /ApplyConfig=C:\UserConfig.json /NoMaster

Hi, after the reboot command when all my calssroom PCs shows the desktop if I hit "F5" then I can get back them all visible in veyon master. This is only a small issue but wasn't present in 4.7.4 release. Have a good day.

You could easily minimize the demo window and control the computer as normal.

Hi, can you please check the permissions on the key files? Did you export the private key from one Veyon Master to the other one?

Sorry for the late repply... Disabling "fast startup" did the trick for me. The replacing of dash with colons didn't seem a good idea, cause for the Lenovo's it worked like that. Only the Dell's were the reluctant ones, so it seemed to be a station configuration problem.

@lmoellendorf Can you try passing -DWITH_PCH=OFF to CMake? Which version of CMake are you using?

@PowerBauer What operating system? Key authentication? Do you assign it by hostname or IP address? If you are using key authentication, have you set two keys on the master that you want to control, and only the public key on the master? Try to set it up based on that, that's what I looked at first. link text