Windows 2012 Server, Update error 80072EFE

A new installation of Windows 2012 as a guest inside HyperV 2019. When trying to update I get the 80072EFE error.

This error indicates a network timeout but internet is working OK. I've ruled out antivirus, firewall, router/gateway filtering, incorrectly configured time/date etc.

When looking at the network traffic generated during unsuccessful update attempt I see a successful TCP handshake between the server and microsoft's update server 40.70.224.149. However after the handshake the Windows 2012 server sends a Client hello packet and the microsoft's server answers with a RST and ends the connection.

This happens a few times and then I get an error 80072EFE.

I have two more Windows 2012 servers (for a lab) installed from scratch and the same thing happens on them as well.

Any ideas ?

Ok, so I found the solution to this problem. Basically, I checked the update history of a correctly working Win 2012 server to try to find a clue. The oldest entry in the log referenced a KB2937636, a Windows update agent.

I manually downloaded and installed that update on my non working Win 2012 servers. After that, the servers started updating correctly.