I upgraded an application only to find, when finished, the new version was not compatible with my operating system. Therefore, I can no longer use the application. Is there a way to back-date the operating system so the upgrade never happened? I know you can do it on PC's but unsure of Mac. And can I upgrade the Operating System without having to buy a newer computer?
Do you have a TimeMachine backup with the previous version of the Application? If so, just restore it from the backup. If not, do you have the original installer or installation media for the app? Does the app developer offer a site with archived versions of their installer to download?