With the introduction of support for macOS 15, we have ended support for macOS 10.x.
If you are still using older versions of Adobe Illustrator, such as Illustrator 2020, on higher versions of macOS 10.x, such as macOS 10.15, it’s likely to function correctly. However, Astute Graphics can no longer guarantee this, and is not able to provide technical support for pre macOS 11 operating systems.
Full compatibility information can be found here.