For some reason my application folder is a Read Only and it's locked, and I can't select unlocking it. Yes, I am the admin of my computer so I don't know whats going on.
Try clicking on the applcations folder then get info (apple i). Click on th ownership and permissions arrow and there should be a bunch of menus. from there you should be able to adjust the acess to give your selft read write back if its gone..