I've now discovered that my copy of WUMT will no longer work now even in offline mode, with the wsusscn2.cab from 2019 which used to work a few months ago!
I'm now just getting "An error has occurred: 0x800B0100 No signature was present in the subject" as I was with the later versions.
I have an even earlier version of the cab file, from 2018, which also definitely used to work, and that's not working now either!
What's happened here?
All the versions I'm trying to use are SHA-1 signed.
For me disconnecting from the internet and rebooting before doing a check for updates worked. I am using the wsusscn2.cab signed on July 14th 2020.
Seems that the Windows Update Agent is doing some kind of validation that fails if there is an internet connection.
On decommissioning of update servers for 2000, XP, (and Vista?) as of July 2019
in Windows XP
Posted
For me disconnecting from the internet and rebooting before doing a check for updates worked. I am using the wsusscn2.cab signed on July 14th 2020.
Seems that the Windows Update Agent is doing some kind of validation that fails if there is an internet connection.