How do I fix WHS 2011 failing to install KB4535102; return code 80092004?

@Moab got me pushed in the right direction. Thanks! 👍

Turns out Windows Updates are now SHA-2 signed. If your server doesn't have the proper updates to process SHA-2 signatures then updates will fail.

So, to fix things, two updates need to be installed:

• KB4474419 ⏬ download
  ^{SHA-2 code signing support update for Windows Server 2008 R2, Windows 7, and Windows Server 2008}
• KB4490628 ⏬ download
  ^{Servicing stack update for Windows 7 SP1 and Windows Server 2008 R2 SP1}

Once installed SHA-2 signed updates will work.

Last step...

• Rerun Windows Update and KB4535102 will install successfully.