hi - I think I have the same problem... attached is a screengrab of what the Open dialog in Acrobat Pro DC (build 2015.007.20033 running on OS X 10.10.3, on a Late 2013MBP Retina). The lower section of the dialog can't be resized, and the top right section flickers. It's the same no matter which of the View modes (grid, list, panels, preview) is selected, and as rshhd says, it makes locating the right file a challenge. I've tried searching for the same issue around the web, but not found anything so far... if anyone can point to a solution, I for one would be very grateful. About to try uninstalling / reinstalling.