Question

I installed the most current version, but the iOS on my iMac is not current enough to use it, and does not appear to be updatable at this time. How can I go back to the old version of UC?

Answer 1

Use this link, 

https://www.presonus.com/products/StudioLive-64S/downloads

The press Show / Hide all versions of software downloads for macOS 10.15 Catalina to see all versions.