I'm not sure either except that all I've done is update to the latest version of both LR and PS (including a system restart). And BTW, it takes restarting PS in order to view an edited image as it should be. Just saving, closing, and then reopening an image yields the same total white 'overlay' or whatever it is.
Actually, I failed to mention and update my profile accordingly, that I'm using OS X 10.11, whether that has anything to do with anything, or not.