Blocks suddenly appeared that deleted chunks of each layer - HELP

[AndyKehoe]

I was working on a digital painting, and when I tried to merge 2 layers, these weird boxes kept showing up. No matter what I did, any merge would bring up these boxes that seems to be filled with parts of the painting. 

So I saved and restarted Photoshop. When I loaded the painting back up again, there were the boxes but instead of being filled with color, they deleted chunks of each of my layers.  Irreparable damage and since I saved it before I quit, there is no other version. I put so much time into this I really hope it isnt ruined.

I've never seen anything like this. Has anyone seen this happen before?

I really hope I can salvage this. 

Appreciate any input. 

-Andy

[TheDigitalDog]

First, try disabling GPU in the preferences (Preformance tab). Any better?
If not, go to Preferences > Technology Previews... and check "Disable Native Canvas" - then restart Photoshop. Better?
If not, recalibrate and build a new ICC display profile, the old one might be corrupted.
If you are using software/hardware for this task, be sure the software is set to build a matrix not LUT profile, Version 2 not Version 4 profile.
If turning OFF GPU works, it's a GPU bug and you need to contact the manufacturer or find out if there's an updated driver for it. 
Also see: https://helpx.adobe.com/photoshop/kb/acr-gpu-faq.html

[AndyKehoe]

Unfortunately none of those things worked. Something literally deleted blocks out of my layers. Tried moving the layers to a new document and the layers still have the deleted boxes.

[TheDigitalDog]

If you duplicate the document and flatten, what do you see? 

[AndyKehoe]

Still there after flattening. I have an online backup going but unfortunately it only had the file when I first began the painting. So at this point, I'm just going to accept that the document is totally screwed up and I'm now working to retouch and repair it by hand.

Luckily I took a screenshot pretty recently so I can patch some things in. Resolution is way worse, but at least its something to work with. I'm also going to start saving to the cloud so I can go back some versions if I need to in the future.

Really does bother me that I have no idea why this happened though. Very strange. Been using Photoshop for close to 27 years and I've never seen anything like it. Unsettling. 

Thanks for the help and the suggestions! Appreciate it. 

-Andy

[J453]

Are you saving locally or to a network drive or server? Do you have any sync agents/folders on your computer (dropbox, google drive, etc)?