Why does my backup agent installation fail with an error message about an Unsupported OS super type?

A backup agent installation fails on a Windows 2022 device and the error message indicates Unsupported OS super type UNKNOWN.

The current release of the Backup Portal requires that servers that use Windows 2022 connect with the backup agent version 9.0.

Install the backup agent version 9.0. Follow the instructions in Installing the backup client in Windows® and download the executable file for the IBM Cloud Backup for Classic client for version 9.0.