Please go to the Apple logo at the upper left of your computer screen to About This Mac and give me this information:
Terminal in Applications / Utilities
Bookmark this page
Let me know CS 5 is not really supported in El Capitan but this may work.
I did not Accept that offer because I cannot call right now. I can connect by remote which would be easier for both of us. If not I can Opt.out. That is the screen you are supposed to see. I also have more information you will probably need to upgrade to the latest version of Photoshop :