Have both PS CS4 and CD6 on Mac OS X 7.5. Just upgraded to Yosemite. Now PS4 "license stopped working". Only have PS4 upgrade disks because I originally bought PS ages ago and only bought upgrades since. Need to work at least long enough for me to get my custom brushes/patterns, but I would like it to work regularly to use Mustek TWAIN (32 bit)@scanner.