The other day i ran into a problem with Microsoft WSUS Server.

I had to manually import a particular update from the Microsoft site.

The import / download dialogue started but then showed the following error:

So I tried to figure out, what was going wrong, but couldn’t find any hints in the servers eventlogs.

Thanks to this article by Peter Kirschner (in german) the solution to this problem was quite simple: https://www.cubido.at/blog/windows-server-update-oktober-2019-und-tls-error

I just added the recommended registry key, rebooted the server, and the import of the update worked flawlessly.

reg add HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 /V SchUseStrongCrypto /T REG_DWORD /D 1