Use of "Merge Visible" into a new layer is not functioning right.
The keyboard command is, Shift+Option+Command+E. (Control for PC)
This "Merge Visible" SHOULD create a new Layer that contains visible items.
NOTE: (CS6 does this without any problems)
The idea or use is to turn off all layers that need not be visible and merge layers photoshop cc.
This is extremely useful when masking and compositing.
I discovered that CC will not allow this, in fact Shift+Command+E is not working properly either.
IF.... you make a duplicate layer of a layer that has a mask and select both those layers, you can get it to work. (if you wish to call that "working")
HOWEVER.... if you turn off unneeded layers and select all layers neither Shift+Option+Command+E OR Shift+Command+E functions properly. (no reaction)
Tested on Mac Pro running latest version of OSX Yosemite and verified on two separate computers. (not a computer hardware problem)
At the moment, I have not tested Mavericks or El Capitan but will later.