Photoshop 9

I have a Mac Pro 10.11.6 and I have the Photoshop Element 9 that was working perfectly, but suddenly, it shows a message that some of the application components are missing from the application directory asking to re-install. I have tried to reinstall with DVD but isn't working. At this point, I don't know how to solve my problem. I don't want to buy another Photoshop App. Is there any solution to solve my problem?