Did you install it from the original installer or did you migrate? Migration does not work with Adobe programs. In such a case you have to use the Creative Cloud Cleaner Tool to whipe out anything Adobe and install from the scratch.
CS4 is not compatible to OS X 10.10. It might run occasionally but you can be sure that it will not run always. Minimum is CS6, but CS6 does not support Retina displays. I would recommend to upgrade to the Creative Cloud as the CS6 is now old and will cause soon the same problem what you experience between CS4 and Yosemite.