Not able to view all photos after Big Sur update (previous photos library stores on an external HD)
After updating to Big Sur on a Macbook Air (Early 2013 or 2014), I now am unable to view all my photos which were perfectly sorted into albums etc. on Sierra.
All the albums appear in the photos app on my Macbook, and some of the photos (6,000 or so) but not the other 30,000 or so that were previously in my library. What is going on? Looking at my external HD, the photo library seems to take over 300 GB so I believe all my photos are still on there somewhere, but don't seem to appear in the Masters (when going into show package contents) or in the photo app library itself.
Please help! Will I need to revert back to the previous software to see my photos again or?
Cheers
Sarah
MacBook Air 13″, macOS 11.7