One of the problems I had is my Logitech mouse was causing issues in El Capitan. Logitech doesn't have updated drivers yet. It was causing a lot of problems. The other thing is that El Capital is not letting me run 2 monitors. When I hook up two monitors I keep getting the login screen. I have separate graphic cards for each monitor. I have checked both cards.They both work properly. Its only when I hook up two monitors the the problem of the login screen pops up.
In response to my first initial inquiry about Photoshop not working, it was more than that. It was Photoshop, Aperture, Illustrator, Microsoft Office, my e-mail, all of these things were closing and giving me a new login screen as discussed above. It has something to do with hooking up two monitors.
I am waiting for a response from Apple on this.