Hi Chin Yan
CAS servers have backward compatibility for AMDs but not forwards. You should never connect a future major release AMD to an older release CAS. It is generally only ok to do this with service pack releases.
The full backward compatibility can be found here - https://community.dynatrace.com/community/pages/vi...
Is there a reason you don't want to upgrade the CAS at the same time? Best practice is to keep the whole estate on the same version.
Thanks for the clarification. I was scared that if anything happens during the upgrade of CAS and the data within will gone.
Anyhow, will upgrade both CAS and AMD together once I backup my data. Thanks again.