I am a Creative Cloud Photography plan subscriber. I just upgraded my Windows desktop running 64 bit Windows 10, to a Dell 5K (UP2715K) monitor powered by an Nvidia GTX 960 based card. Because this is a hi-dpi display, i have Windows, and Photoshop CC 2015 set to 200% UI scaling. Unfortunately, the top toolbar is broken in this configuration showing a large black rectangle over three quarters of the toolbar. See attached. Please address this in the next update.
Caesar