“Photos Library.photoslibrary” is in iCloud Drive, and needs to be moved to a folder on your Mac to open.

Just do as the error message suggests and drag your Photos Library from iCloud Drive to your Pictures folder or another local folder on your Mac.

A Photos Library must not be stored on iCloud Drive; it is not safe to do so, as the syncing with other devices across iCloud Drive can break the internal links in the library and damage it.

If you want to sync your photos with iCloud across your devices, use iCloud Photos. Only iCloud Photos can store your photos in iCloud and sync the Photos Library safely across all your devices, independent of the platform and the system version, without breaking the internal links.

See the warning here: Move your Photos library to save space on your Mac - Apple Support

"You can't store your library on a storage device used for Time Machine backups. And to avoid possible data loss, don't store your library on a removable storage device like an SD card or USB flash drive, or on a device shared over your network or the internet, including over a cloud-based storage service."

The previous versions of Photos did not warn us, when we moved the library onto iCloud Drive, but starting with macOS 13 Ventura the library would not be uploaded to iCloud, when we moved it to iCloud Drive.The cloud status has been unable to upload. And since Sonoma we cannot open the library there at all.

Same!!!! WTF Apple????

But where is your Photos Library now? If your Photos Library is on iCloud Drive you have to move it to a safe location. You can see, where your current Photos Library is, when you launch Photos while holding down the options key ⌥. This will bring up a list of Photos Libraries. If you select one, you can see the path to the library at the bottom of the window.

It may not be obvious that the library is on iCloud Drive, if you have enabled iCloud Drive in the System Settings > Your Apple ID > iCloud > iCloud Drive and also the option "Desktop & Documents". Then your library will even be on iCloud Drive, if it is sitting on your Desktop or in Documents. The older system versions did not warn us, if the library has been on iCloud Drive, even if it could get damaged there. But the macOS Sonoma is finally checking, if a library is in a safe place and does not open it in an unsafe location to protect it from getting corrupted. That is why you are getting the warning now, even if you never moved your Photos Library. It may have been in a dangerous place along and it is high time to rescue it.

When you find your Photos Library, drag it to the Pictures folder, then double click it to open it in Photos. Can Photos now open it?

No Photo Library is safe on iCloud Drive. The syncing can damage the internal links, when iCloud Drive is syncing any changes between iCloud and the local copies.

And since macOS 13 Ventura it is futile to move library to iCloud Drive. iCloud will simply not upload it to iCloud. If you want to store a Photos Library in iCloud Drive as a remote backup copy, you will have to disguise it, so the system does not recognize it as a Photos Library. When I wanted to use iCloud Drive to transfer Photos Libraries between my Macs. I created a folder containing the library and compressed the folder and moved the compressed zip folder to iCloud Drive. The compressed folders are not damaged by the syncing. But before we can use the library, we have to remove it from iCloud Drive and uncompress it.

But macOS 14 Sonoma is now preventing me even from compressing folders with Photos Libraries inside.

Thanks for the reply. The library is on my desktop, having been copied over from an external drive. The thing is, after I turned on icloud syncing some time ago, I was surprised to find that not only had it created icloud copies of my documents and desktop folders, but it apparently eliminated the local folders. That may very well be the way it's supposed to work, but I wasn't expecting it. I'm used to cloud models like box or dropbox that dynamically sync cloud to local files. More recently, when I tried to open the library to export it, I was faced with the error message and noticed that finder shows the cloud-with-a-slash-though-it icon next to the library. Fortunately, since I posted this question I was able to locate the external drive with the original library file. Still some issues, since it's in a legacy format that can only be opened with an older system, but progress.

I saved this as a new user tip: If you are seeing the error message "The Library could not be opened. The Library is on iCloud Drive… - Apple Community

Is it safe to save a different photos library, one that does not sync across devices, in iCloud Drive?

iCloud synchronizes your files among all your devices. (Before iCloud, I used a different service for this same purpose. I'm not sure, but Dropbox, and certainly others, now operate the same sort of service.) iCloud Photos is a separate part that synchronizes pictures among all your devices. When you "move" a folder from your drive to the iCloud folder in the sidebar, it makes a copy there so that all your devices can access it. Copies are also kept on each device (depending on available storage) so that access can be faster. The place where this stuff is kept on the Mac is sort of hidden.

iCloud Photos is a separate synchronization system, so the Photos Library cannot be used by Photos from iCloud Drive. You have seen that the little iCloud icon indicates it's not there. It's taking up space on your drive, but you can't use it. Drag it back to your Pictures folder!

You apparently will now have several (?) Photos Libraries. You will need to sort them out to see what you want to do with them. So--close Photos and then option-click on the Photos icon. A dialog will open that shows your Photos Libraries (at least any that Photos can find.)

One will be labeled the "System Library." This is the one that connects with iCloud Photos, if that has been selected.

You can use this dialog to see where each Library is, and to open different ones to see what's inside.

Tell us what you find...

brendan.oman wrote:

Is it safe to save a different photos library, one that does not sync across devices, in iCloud Drive?

No.

léonie is correct.

If you are looking to use Photos app, and not use iCloud Photos*, and do want to use hosted storage, then you are limited to using some other photo sync service and photo hosting service, or some other backup service.

Backup services such as Time Machine and Carbon Copy Cloner are potential options combined with local storage. Time Machine can back up to a storage server on the local network. CCC can back up to local storage, or to remote storage.

*If this is possibly related to sharing an Apple ID with others, don’t do that. That shares everything. Everybody needs their own Apple ID.

I received the identical message, and the previous answers don't capture the problem. I was trying to opening a library file on my desktop. So if there is also an icloud copy, moving it from there would just duplicate what's already stored on my computer, wouldn't it?

You may not have the same problem at all-- so it might have been better to start a new post. In any case, we know the error message you got, but not the circumstances. Where, exactly, is your Photos Library? Is it in the Pictures folder?

Do you indeed have a Photos Library in iCloud Drive? There should not be one there. Is this a copy of one in your Pictures folder? Move the iCloud Library (if you have one there) to the Pictures folder-- you may have to change the name.

How did you get this error message? Does it happen just as you open Photos? What happens if you double click on the Photos Library in your Pictures folder (if there's one there?)

Give us more information and we may be able to help...

Opened like a charm. Thank you so much for the guidance and for clarifying how the system works. I have a much better mental model now.

Glad it worked! A "better mental model" always helps!