external drive with Photo Library is damaged by Photos when making external library the default
New MacAir (M2). trashed my external drive with photo libraries when converting to the new operating system format. No warning that this can take a while (16+ hours). During that time, OpSys claimed external drive was improperly ejected (it wasn't). But I believed it and unplugged the drive. This trashed the library on the external drive. I had to recover from my backup on my old computer and successfully converted to the new format (this is when I discovered it took 16+hours).
So I added new photos and then I decided to make the external library my default. Photos warned me that it needed to resolve partially updated photos with the Cloud (no problem, Cloud is disabled). Again, Photos didn't give a warning and took hours. During that time, the OpSys gain complained I had improperly ejected the drive (I didn't - it still showed on in Finder and I could see it's content). I again waited several hours and killed Photos but the "change" seemed to still be running. This lasted overnight and still I couldn't access Photos (I got a 5416 error). Finally told OpSys to eject drive (force eject) and now I still get a 5416 error every time I try to access the external library
Not impressed with the Photos app. I'm worried I lost a lot of data.
I have tried to run the Disk Repair utility - it claims it can't unmount the drive. I tried to run the Photo Library Repair routine and it also claim a 5416 error).
What do I do?
MacBook Air, macOS 12.6