0

I upgraded to Windows 11 now my VPN connections fail. They were working right before the update. The error is...

The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.

  1. I've tried everything mentioned in this article
  2. and in this video
  3. Uninstalling kb:5009543 mentioned here didn't work either.
  4. After I did all the items in this article I did get a slightly different result, it now says "Connecting to [IP]" and spins for a minute or two then shows the same error. Before I would get the error immediately.

Any help would be appreciated.

Gordon
  • 103
  • 5
  • 2
    I don't pretend to speak for everyone but I'm not following links and/or sitting through videos to guess at what you did, please document clearly what you tried, what you expected and what happened. Also, what do the server logs say – Ginnungagap Jan 13 '22 at 00:23
  • @Ginnungagap I usually do that. Just trying to be efficient. I can list it all out when I get back to be a PC but it will make this post about 10 pages long. – Gordon Jan 13 '22 at 00:25

2 Answers2

0

You updated to Windows 11 on the wrong day. There is a current bug in Windows 11 that has broken L2TP VPNs. It's not just you: it's being pushed out in Windows Update.

user165568
  • 270
  • 1
  • 2
  • 9
0

Figured it out after this article was published yesterday. It wasn't directly related to Windows 11. I just happened to upgrade from Windows 10 to Windows 11 the same morning that security vulnerabilities and bugs update KB5009566 dropped. That is what is breaking L2TP VPN connections. If you uninstall it, which I don't recommend, they will work again.

Run -> cmd ->

wusa /uninstall /kb:5009566
Gordon
  • 103
  • 5