unable to open photo after having installed version 11.5

Your problem is the ExFAT format. This is not compatible with photos libraries. It needs to be APFS (Or MacOS extended (journaled)) (Not case sensitive)

Yes, I know you've used it up until now but the problem with incompatible volumes is they can work - until they don't. Operating the library on one can result in a gradual build up of errors in the library until it eventually stops opening, otherwise malfunctions, or a later OS version decides it can't work with it. To be honest it is ridiculous that the app doesn’t detect an incompatible volume, and refuse to work with it (with appropriate message) until you sort it out

The problem is if you've copied it to the MacHD and it still doesn't work, I'm not sure what your next move is. Are you sure the copy has worked correctly (are package contents the same?)

Are you syncing your desktop with iCloud? If so, also not compatible. Try moving it to the pictures folder and see what happens. In fact, move it to the pictures folder anyway.

If that gets you nowhere, then do you have a copy you can restore from backup to your pictures folder?

Failing that, can you install your previous version of MacOS on an external SSD, then use that to repair the library (On a correctly formatted drive) then try that repaired/correctly formatted version with your 11.5 (I know this is not an attractive solution, but I'm not sure where else to go. Unless you already have a second mac with an earlier version of Big Sur on it you can try)

See

https://support.apple.com/en-gb/HT201517

Hi Tony

I confirme, I was in the case, my library was stored on a Exfat volume, I copied it on a new external volume formatted on APFS.

I opened the library on repair mode (CMD + ALT), and after, Photos application restored again all pictures correctly.

Regards

What happens when you try? Any error messages? Where is the Library stored? Can you create a new Library?

What format is this other drive? How are you connected to it?

Thanks for the quick reply, @Yer_Man! Original library is on an SSD connected via USB, ExFat formatted. I get the same results from the copy I've saved to my desktop on the MacHD. Worked fine until the 11.5 update.

When I open Photos I get:

Photos was unable to open the library “Photos Library”. (4302)

When I copy the library to my desktop (original is on a separate drive) I get:

PHPhotosErrorInvalidState

Appreciate the reply and the guidance. Will get to work and report back to the community with the outcome.

Good news. Thanks for the confirmation 🙂

Took a few tries (and the purchase of a new HDD) but this worked for me as well. Many thanks for the previous replies!

Again, thanks for confirmation