I have exactly the same case. Have you found the solution?

@Janusz-Konefal Have you tried temporarily turning off your firewall? If you are using Windows Defender that has been known to cause a problem.

Yes, I did it several times, even turned off the firewall on my router, unfortunately the problem didn't go away

It is not a firewall problem, it may be a Windows 11 compatibility problem...?

It is not a firewall problem, it may be a Windows 11 compatibility problem...?

Several users have reported installing and operating their Vegas software under Windows 11 without problems.

@Tomasz-Socha @Janusz-Konefal What part of the world are you?

Several users have reported installing and operating their Vegas software under Windows 11 without problems.

@Tomasz-Socha @Janusz-Konefal What part of the world are you?

Poland, I think Janusz too ;)

I found a solution to this problem myself.
Here's what I did: I disconnected my desktop from the internet (from router) and reconnected but this time on my phone using the GSM network.
Activating Vegas Pro and SaundForge went smoothly.
Now I would like to listen to some proven tips on how to configure Vegas Pro so that it does not crash so often (because that was the reason for reinstalling the program).

@Janusz-Konefal You should create a new thread with your problem. Include info about your system hardware and the media you usually use. https://www.vegascreativesoftware.info/us/forum/faq-how-to-post-mediainfo-and-vegas-pro-file-properties--104561/

@Janusz-Konefal as advised by @RogerS please post your different issue in a new thread as it won't be noticed in an unrelated thread, which was actually started by another user. Click your avatar (upper right corner) and choose New:Post. Thank you.

@Janusz-Konefal
You can also go through points 8, 15 or 16 in this Troubleshooting Guide, depending on the occasions when Vegas Pro crashes on you.

https://www.vegascreativesoftware.info/us/forum/vegas-pro-faqs-and-troubleshooting-guides--104787/