@Andrea-Pessina - You most likely need to allow TCP port 11100 inbound/outbound on both the master and client servers. That helped me at least.

@TonyPSchaefer Yes this is exactly what im trying to figure out too. We have multiple Windows servers that students RDP into. My instructor wants to be able to remote view all of the machines with the students logged in. I actually installed the veyon master in the classroom environment and now all I get is a black screen even though its connected. I get the lock screen on different install in a separate subnet so two things to figure out now.

@tobydox Thanks for your work on this. Your post references 4.4.x and I'm currently using 4.7.4. I've read the articles you linked to and still cannot get Veyon to see into PCs that are being accessed via RDP. My setup: 12 physical PCs for students and one for the teacher. Everyone is remote, even the teacher. Teacher connects and uses Veyon to monitor the students. Students connect via AnyDesk or Remote Desktop. We prefer AnyDesk but sometimes have to fallback on RDP. The teacher cannot monitor the RDP students. In Configurator, I set up the Computers as "192.168.1.100:11101" for example. I've tried 11102, 03, etc. and still have no luck. Is there more? What am I missing?

@fh123 Maybe I'm facing the same issue. As a workaround, instead of restarting the machine, try to unplug and plug the USB mouse back. That seems to work. Have a good day. Carlo.

Solved - application MagicInfo and his uvnc modul made the problem. After killing everything run!

@Prakash-K i'm having the same issue.. Please update once you solve this issue.

@lcrosier Hi, I have this issue starting from Veyon 4.7.5. Hitting the "F5" key on the master PC helps to make all clients visible again. The only temporary solution for me was to roll back the teacher PC to Veyon version 4.7.4, leaving the student PCs with Veyon 4.7.5. I hope this helps. Have a good day. Carlo.

@DCteacher You are very welcome! So it was the public key, good to know. I'm happy you have solved the issue! Have a good day! Carlo

Hello, Thank you for your attention. The options you mentioned are already configured, I researched a little more and found this topic that solved the problem, https://github.com/veyon/veyon/issues/146#issuecomment-342851916 Thanks again.

@jesse26j I downloaded it from the veyon website, not from github. It says version 4.7.4.0 in Windows.