Thought I'd share this little tidbit with everyone: I just noticed the upgrade pop-up on my screen while processing images. When I finished my work, I went in and clicked the "Upgrade All" choice, then left for a shoot. Upon return everting was done and I clicked on LrC to open. My Win10 pc immediately froze up. After several attempts and repeat -freez-ups, I finally realized that I needed to open LrC "as an Administrator". This simple step allowed me to run LrC, convert the lcrat to the new version, and enjoy life.
1. Before you upgrade - back up your .lrcat!
2. Reboot your pc before starting the new LrC version, and start that version as an administrator.
Bug, Crash or freeze, How to, Problem or error, Windows