A .psd error message?

I have a .psd file that is getting this error message "Could not complete your request because it is not a valid Photoshop document."
This is the first time this has happened on my Ps, CS6...and I've looked elsewhere to get some help.

And I was just working on this file a while ago, so I'm not sure what went wrong.
It is located on one of my USB Flash Drives, and I have heard that certain USBs tend to cause these things....yet this is the first its happened. How to do recovery for photoshop?

rickharris18 days ago