I can't get CS4 Illustrator to open on my old Mac (OS El Capitan). The message i get is....The localized resource files for this application could not be loaded. Please reinstall or repair the application and try again.
When it was done installing Application Disc 1, it prompted me for Disc 2 but wouldn't let me remove Disc 1 because it said it was in use. So I'm wondering if the installation of Disc 1 was not completed properly ( The resource folder seems to be part of Disc 1).
Some people might have got it to run, but they probably used the downloaded installer, which is not available anymore. Maybe you have more luck when you turn that disk into a virtual disk, but basically you're on your own there.