After migrating Photos Library from Sierra to Big Sur, library almost empty
I'm updating an old Sierra iMac to a new Mac Mini w/Big Sur. I copied the old Photos Library file over to the new Mac and placed it in the Documents folder. I then double-clicked it to open it. A dialog appeared saying something to the effect that it was updating the library. When the progress bar got to 12% complete, it appeared to stall. However, I could see my 4GB Photo Library file reducing in size via Finder. I watched the size fall from 4GB to just a few MB. Then the progress bar quickly made it to 100%.
When Photos opened after the conversion was complete, I had only 19 photos, where the original 4GB library has over 9,000 photos. Anyone run into this?
Mac mini 2018 or later