macOS Big Sur 11.5.1(20G80) updated and then photo cannot open photo library nor create a new library

Hi - You are going to have to move the library to a volume with a compatible format.

1 - Backup your existing library. You are going to be copying the whole thing at least twice, and then possibly having a repair run. As a large data structure this will take some time, with a risk of data loss while it is ongoing.

2 - You will need to temporarily copy your library somewhere else WITH A COMPATIBLE FORMAT. This could be your system drive if you have enough space. Or a second external drive (USB or Thunderbolt), which is formatted APFS or MacOS extended (journaled). This might mean you need to buy (or borrow) an additional external drive. If so, you could use the new drive to run the library in the future, saving yourself one pass of copying the library.

3 - Reformat the external drive using disk utility. Again APFS (suggested for SSD) or MacOS Extended (journaled) (preferred for spinning drives). Do not use Case Sensitive. Be especially carful to choose the correct drive to format. Formatting completely and un-recoverably erases the contents, so you don't want to format the wrong one. Ideally unplug all other external drives, and make sure the drive you are formatting is in the external section of disk utility.

4 - Copy the library from the temporary storage to the newly formatted external drive. (You can skip this if you are going to leave it on the new external drive)

5 - Open the library on it's new home by holding the option key while starting photos. Go to photos preferences, and click the "use as system photo library" button.

Read also:

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

What exactly happens, when you try to open the library? Do you get an error message? If yes, which message?

Where is your Photos Library stored? On an external volume or in your Pictures folder?

What happens when you try to create a new library? Where does it go wrong?

Are you launching Photos by clicking the the Photos icon in Applications, or are you using an alias on the Desktop or in the Dock? Try to launch Photos by clicking the app directly in the Applications folder, so you can be sure to launch the version installed by the system upgrade and not an outdated link.

Hi

What format is the external volume. It needs to be MacOS Extended (journalled) or APFS, and be able to have the ignore ownership flag set, to be compatible with a photos library. Most new drives come formatted ExFAT by default which is NOT compatible.

Hi

I've seen reports from quite a number of people now that 11.5 will no longer open photos libraries on ExFat (and probably other incompatible) formats. Although inconvenient right now it is probably a good thing for the long term as it will force people to use a compatible format, and eliminate the risk of any further damage building up in the library.

So the solution is to backup the data? Well first of all it's extremely slow at reading my harddrive so trying to backup 1.2tb has been extremely painful. I've been uploading my data to the cloud (strong arming me into paying for 2tb of storage) and in the process many of my files have disappeared and/or become corrupt. I have spent about 40 hours dealing with this and it's become an utter joke.

Do you have a solution to recovered/fix my files, tried Disk Drill and it's literally warned me my harddrive is on the verge of breaking? Apple has seriously disappointed this time and I'm not sure why they've done this!

So the solution is to backup the data?

It's difficult to think of any sensible computer user who doesn't back up their important data, at least once.

You're not "strong armed" into paying for 2tb of Cloud storage. You can back up to an external HD. Much faster too.

Yeah I have the exact same issue with the same Mac Mini and external SSD drive that is formatted ExFAT !

Worked fine with MacOS 11.5.0 but no go with 11.5.1 darn!

The library needs to reside on a volume formatted Mac OS Extended (Journaled) or APFS.

Thanks for the replies guys.... I am a total novice: Now what to do as my entire library is on the external drive that's ExFAT?

Thank you for the detailed reply.