When upgrading the vSAN witness appliance from version 8.0.2, 22380479 to version 8.0 U3b - 24280767, an error occurs.
"The CPU on the host is not supported by the image. Please refer to KB 82794."
Note : The link to the above kb article is now contained here but the message in vSphere remains the same : https://broadcomcms-software-agent.wolkenservicedesk.com/wolken/esd/knowledge-base-view/view-kb-article?articleNumber=389689
vSAN 8.x
Having downloaded and installed the vSAN witness appliance (distributed as an OVA file), the appliance shows an earlier version of the CPU than what is running on the physical Host where the appliance is running.
This issue is explained in the following kb : https://broadcomcms-software-agent.wolkenservicedesk.com/wolken/esd/knowledge-base-view/view-kb-article?articleNumber=389689
Since this is an embedded Witness appliance running on the Host, upgrading the HW version allows the CPU version to match what is running on the physical Host and allows the upgrade to proceed.