When I launch app I get this message; "No document types have been found in the Configuration/DocumentTypes/folder. The MMDocumentTypes.xml file may be missing or corrupted. The application with exit now." Should I uninstall / reinstall the app? It's runs fine on my iMac OS X v10.6.8.
Has CS5 ever run on Yosemite?
That's what I'm trying to find out.
Others have run into all kinds of problems with CS5 programs under Yosemite, there's quite a bit online about it.
If you can't get it running after a Clean & Reinstall: Use the CC Cleaner Tool to solve installation problems | CC, CS3-CS6 it might just be too old to work correctly.
It's approaching "ancient" as far as Yosemite is concerned.