Cumulative Update for Server 2016 fails to install

[45support]

On my Server 2016 machine, the cumulative updates won't install. Each month, a new cumulative update arrives, and if you click install it will go through all the steps but upon the restart...it fails and rolls back. Any idea why?

[#2]

It is hard to say why it failed from what you explained.
However, you may look into Windows Update log files, take a look at:
https://docs.microsoft.com/en-us/windows/deployment/update/windows-update-logs