The CU for Windows Server 2016 July 2017 (KB4025339) failed to install on Windows Server 2016.
It's a pretty big update - over 1GB.
However the maximum run time of the update was incorrectly set to 10 minutes. Raising this to 60 minutes solves the problem.
I came across some other challenges while troubleshooting this issue.
- The Windows Update log file is no longer available by default on Windows Server 2016. The file can be exposed using the PoSH cmdlet get-WindowsUpdateLog
- However executing this command on the server resulted in this error:
Cannot find path "C:\Program Files\Windows Defender\SymSrv.dll" because it does not exist".