For those familiar upgrading Exchange 2016 through the command line, you may have noticed that the command below does not work with CU22:

  • setup /mode:Upgrade /IAcceptExchangeServerLicenseTerms

There is an additional requirement that has to be done on the command line, I have highlighted it above but you can see the updated command below:

Stop for a minute. There are more requirements that you need to install before you run the CU22 Exchange 2016 install. The new requirement is:

  • IIS Rewrite 2.0

If you head over to the docs site, you can download the prerequisite from there. Once you have installed it, you need to reboot your server.

Also take note that in the command line installation, it will perform the "Organization Preparation" before continuing with the upgrade, here is a snippet as per the image below:

Always test the Cumulative Updates in a lab if you can. I have been running this in multiple labs and not seen any issues thus far. I have one installation with the Diagnostic Data Off and the other one On.