Open a RAW file from Lightroom or directly with Photoshop (Camera RAW 13.2), I could ONLY save the file in .PSD format for the first time. If I make any changes to an existing .psd file created from .cr3 file, and try to save the file (command+S) the second time, I get the "cannot save" program error. So for each little change, I must save the PSD file with a new file name, the only way the saving function works. I even tried to save (save as) a PSD file to jpg, which works, then open the jpg, add a blank layer, then delete a blank layer and save it back as PSD (replace the existing file) I get the same cannot save program error.
I tried to open the same jpg do some changes on the background layer, undo, then save as jpg again, same error.
I tried "open, change, save" with other raw format files, other .psd files (not created from .cr3 ) and old jpgs, saving works just fine by repeating the above process. So the problem seems to be is just with .CR3 files.
Update, I just saved the psd file to my mac pro harddrive, and save function has NO ERROR. so the error as described above only happens when writing to the SSD external harddrive. First time okay, so creating a file is okay but cannot write to it again? So it is not a program error but a hard drive issue? I really don't understand what's going on here.