Trying to override a default OS shortcut key with a Photoshop one. Just got CC and all my previous versions I didn't have this problem. I understand if I go to System Preferences > Keyboard > Shortcuts, I can remove the shortcut, but I just don't have it. The shortcut I want to add is Command +F1. I have successfully added other Command + shortcut keys, but this one gives me the error "cannot be assigned because it is used by os". I am on a laptop and already have clicked on the "Use F1, F2..." checkbox on System Preferences. Thanks for any help!