Illustrator 24.0 and Illustrator 23.1 work with macOS 10.15 (Catalina), but they have some known compatibility issues. You may want to remain on your current version of macOS until these issues have been resolved.
Adobe strongly recommends that customers do their own testing on a non-production partition to ensure that new operating systems work with their current hardware and drivers (printing, and so forth).
If you do encounter issues not already documented here, feel free to report them on our feedback site.
No, legacy/perpetual versions of Illustrator were not designed or tested to work on macOS 10.15 (Catalina). They are not supported in any way for use on macOS Catalina.
Adobe does not recommend that customers using old versions of Illustrator upgrade to macOS Catalina.
Illustrator version 22.0 and earlier will not display in the ‘Older Versions’ list within the Creative Cloud desktop app.
Older versions use 32-bit licensing components and installers. Therefore, they cannot be installed and activated after upgrading to macOS Catalina. Upgrading to macOS Catalina with an older version already installed on your computer may allow the application to function in some capacity; however, you will not be able to reinstall or activate the application after the macOS upgrade.
Before upgrading to macOS Catalina, you may uninstall the older versions as the uninstaller will not work after upgrading. If you have already upgraded to macOS Catalina, you can use the Creative Cloud Cleaner Tool to uninstall older versions.
The ExtendScript Toolkit, which is a 32-bit application, will no longer work on macOS 10.15. The ExtendScript Toolkit has been replaced by ExtendScript Debugger 1.1.0.
When using Illustrator with macOS Catalina, you may face an issue where the application stops rendering panels and documents. Restarting Illustrator may resolve this issue.
If Illustrator asks for your permission to record or capture the screen or access Calendar, Contacts, Camera, or Location, then you can ignore this notification. It's Apple's new privacy protection that apply to the directories containing your calendars, contacts, photos, mail, and messages. For more details, see this article.
Note: Adobe apps do not need access to your Calendar, Contacts, Camera, or Location.