AH-HA! There's a new button to turn on and off layers - I discovered it quite by accident. I will leave the post in case others need to "find" that button. It's at the top of the layers panel to turn layer filtering on/off.
Photoshop CC, Windows 7 Home Premium
I added a new layer - it doesn't show up in the layers panel.
I added a shape - it doesn't show up in the layers panel.
I converted a layer into a smart object. - It doesn't show up in the layers panel.
THEREFORE - I CAN'T SELECT ANY OF THEM!
The document I am working on was created in CS6. It has a frame - WHERE IS THAT LAYER?
Thank you for any help/suggestions.