Photoshop CS6 - When I load the file I link, turn on the visibility of Layer 1 and try to save, I get an error dialog with the message:
"Could not save “Bug.psd” because of a program error."
I had a more complex file to start with, and pared it down as much as possible. I was able to recreate the bug on another computer by recreating the same image. Note that layer 1 has a non-normal blending mode.