https://cdm.link/2019/09/macos-catalina … t-to-know/

From the article

[...]

"How should you upgrade, and when?

Here’s a simple piece of advice: don’t update to Catalina immediately. As with any major OS change, music installers, drivers, and DAWs will benefit from more time and testing. Since musicians have complex and diverse setups, odds are you rely on something that won’t be immediately compatible, or that interactions between tools could create unexpected results.

If you do update, you should absolutely make a full backup so you can easily roll back. Time Machine backups can also provide some ability to remove OS updates.

You can also create an external installation of the OS on any drive that is formatted to macOS extended Journaled. It’s probably worth buying an inexpensive drive to test first, especially with an update this significant.

Macworld has two helpful articles (also linked by Ableton):

How to dual-boot Mac: run two versions of macOS on a Mac
https://www.macworld.co.uk/how-to/mac-s … c-3659676/

How to downgrade macOS from Mojave to an older version
https://www.macworld.co.uk/how-to/mac-s … e-3581872/

If you’re a developer and want to share your compatibility information, please get in touch.

https://www.apple.com/macos/catalina/"