I upgraded from LR 6 to Classic recently and had minimal problems on my desktop. I then loaded it onto my traveling laptop and just got back from a trip and was not able to download any photos shot with my new Sony a7iii onto my laptop. I am able to load photos shot with my Nikon D7200 and D800, When I got home I had no problem downloading to my desktop. I get a message in the grid view on import "Preview unavailable for this file" and upon completion of the download I get another message "files cannot be opened by LR". I have made sure I have the latest updates. Does anyone have any suggestions as to what I need to do to correct this problem?
If you upgraded to Lightroom Classic CC, you indicated that you made sure you have the latest updates. What is the EXACT version installed on your computer. Don't say the latest update. We need numbers!
Go to ‘Help - System Info’ and show a screenshot here.