Edited pictures in Photos turn black
After importing pictures from iPad and iPhon to iMac (Big Sur) and attempting to auto-enhance the pictures, they turn black. Have deleted the .plist as per another discussion thread and photos still turn black. Rebuilt the photos library as recommended in another discussion thread and now they turn green when I use auto-enhance. Upon trying to edit, none of the functions seem to work.
iMac 27″, macOS 11.2