I was searching photoshop repair utility, cause my .psd file on laptop stopped opening. And now it pops up following...Is not a valid Photoshop document. I've used some special features to handle it, but no one of it didn't give me an appropriate result....
Another long-shot technique in Windows is to see if there's a Shadow Copy
of your file (copy from a restore point). Right-click on the file, choose
Properties from the list - in the Properties box, choose the Previous Versions
tab. Hopefully (in theory...) there'll be a useable previous version to choose
from. These instructions are for Vista. If the tab is not there, do a search
for instructions for this feature on your operating system.
In addition some useful resources from Adobe community and other forums dedicated to this trouble...