The only workaround I can find is to stop the Veyon service. This appears to be a bug.

@Barreira I'm pretty sure it's bad code. There's a post on github about this too, and I posted earlier on this forum as well.

So far no responses at all. It's definitely a security issue, and interferes with Excel.

@bonny I can confirm that changing languages doesn't work OK with Greek. I have Windows 10 and the latest version of Veyon installed. When changing language to Greek, usually nothing transfers from my master PC to the client. Sometimes, I have seen it sending strange characters. And the usual shortcut to change languages (Alt+Shift) doesn't work properly.
I resort to using copy-paste to send Greek.

@WCGSTech
Hello
If you use a certificate for SSL authentication it is possible that the certificate has expired, you must renew the certificate with the same key.
Fred

@vinicius-souza Here I do it like this: I link the mac and ips in the settings list, in the bios, it depends on the motherboard model, you need to activate S4 S5 and an option called ErP will work.

@tobydox Thank you very much for your information, it worked. Thanks.

@aonmaster
After 4 hours of uninstalling updates, I found out that the reason was Intel HD graphics drivers for internal graphics. Tried 9.17 version and some other - no succcess. The Motherboard used is Asrock H61M-GS and Intel Pentium G630 CPU.

After adding separate video card (GF6600, the old one) - the probles is gone. Everything works fine as it should.

What it the way to contact the developers, so that they fix this issue?