I'm not a Mac engineer, I am a Windows engineer. I had heard that Mac El Capitan has a massive problem with 32 bit programs and especially with PSE. Adobe no long supports PSE12. I seriously suggest you upgrade to PSE 14 or 15. It's about time. The only thing different in those is the back arrow is at the bottom instead of the top. We all made the change and I still have all the versions from the first day in 1992 when I was a test engineer at Microsoft. I hardly ever use the older ones unless there's a problem I need to duplicate and most of them have had enough of my abuse. Make the upgrade to 14 or 15. Those are much better.