Unable to copy Photos app library from external drive after deleting original on Mac

The hard drive says it is "expat" formatted and says it can be used on a Mac

I wonder if instead of "expat" the disk is formatted ExFat, as there is no such thing as an expat format. Further a Photos library cannot be stored on an ExFat library but must be stored on s disk formatted Mac OS X Extended, Journaled or apfs.

This could be a very real cause of the issues you are seeing.

Rather than trying to use the Finder to copy the library, use a 3rd party back up application to 'back up' the library the Pictues folder. An app like Carbon Copy Cloner or Super Duper are ideal as they make direct copies of the item to be backed up but will also manage most if not all of the issues that arise along the way.

First: Organizing pictures is what Photos is really good at! How does someone make money selling a template? See this:

Organizing photos with Folders & Albums - Apple Community

Back to the problem: Are you sure you know which Library you're looking at?

• Open at the Library Chooser to find where all your Libraries are. Close Photos and option-click on the Photos icon to get this:

Maybe you have more than you think, so here you can see the path to each Library. Only the System Library can connect to iCloud.

• If you have multiple Libraries, you can just go to one and double-click on a Photos Library to run it in Photos. The you can compare them.
• How is your External Drive formatted?  To avoid damaging the Photos Library an external drive must be formatted in either APFS format or Mac OS Extended (Journaled) format. The drive must be connected directly to the Mac by cable, not networked, clouded, NASed, etc. Additionally, the drive can not have had Time Machine on it since it was formatted. There have been so many problems with using incompatible drives that the newest macOSs won't even allow a Library on a non-Mac formatted drive to open, since there is a chance of damaging the Photos database. See this:

Move your Photos library to save space on your Mac - Apple Support

➔ If this drive is in a an incompatible format, stop running Photos with it immediately!  A Photos Library can sit on an incompatible drive, but running it may corrupt the database.

• Like what Yer_Man asked, what happens when you try to drag this Library Package from the external drive to your Pictures Folder?
• How much free storage do you have on your Mac? At System Settings>General>Storage, what does it say?

We have so many questions! Let us know…

That's ExFAT. Stop using Photos on this drive immediately.

To repeat: To avoid damaging the Photos Library an external drive must be formatted in either APFS format or Mac OS Extended (Journaled) format

It's not working because the drive is not compatible.

When I drive claims "formatted for Mac", you can safely store files there and read them on a Mac, but a Photos Library is a complicated package of linked files and internal databases. And these links may and references between the database entries may break, if the file system format does not support it. Photos cannot work safely on a file system with an incompatible format.

You will need an additional drive, formatted correctly, where you can save your Photos Library temporarily, while you format your external drive correctly.

Move your Photos library to save space on your Mac - Apple Support

I have been asking about your use of iCloud, because a copy of an iCloud Photos Library may not include all original image files, if the library has been using "optimize Mac Storage". In that case you may need to sync your library agin with iCloud to recover all originals. And that will bring all your old albums back, which you may not want.

Have you tried using carbonCopyCloner or SuperDuper to copy the library from the ExFat disk?

You need a second external drive, formatted correctly. when we purchase external drives we should buy them in pairs anyway, one drive for the documents and data, and another one for the backup copy of the data.

(2) : What is the error message you get when you try to delete the library? If it is "In Use" restart your Mac, before you try to delete it. But I would not delete any library at all right now, while you have not yet recovered your photos. You may need any older library to recover original image files and videos.

To download your photos from iCloud create a new, empty Photos Library in a supported location with enough free storage: You may want to try the following to get again access to Photos:

• Quit Photos if it hanging or running. Restart your Mac to terminate all processes.
• Now create a new, empty Photos Library:
  • Hold down the options key ⎇ firmly and keep holding it down while you launch Photos by double clicking the Photos icon in the Dock or the Applications folder. Keep holding down options until you are seeing the Library chooser dialog.
  • In the Library Chooser panel click "New" to create a new Photos Library. Select a folder, where you want to keep your iCloud Photos Library, so you do not have to move it again. Moving an iCloud Library is very expensive, as it requires al ongoing new sync with iCloud.
  • When Photos opens, open the Photos > Preferences and click "Use as System Photos Library". You may get a warning, that this will stop the syncing of your previous Photos Library, confirm this.
  • Now click the iCloud tab of the Preferences panel and enable iCloud Photos for your new Library and wait for your photos and videos to come back. Now you should have again a working Photos Library. Wait for the photos to come back from iCloud.

Does this work for you? Can you get Photos to work with a new, empty Library?

I wanted to organize my photos better so I purchased a downloadable template.

What is this and how is it relevant?

I copied my photolibrary to an external drive and then as directed, I deleted the photo library from my Mac.

Why? Where did you get these instructions from?

I've tried copying the photo library back to the picture file but it will not copy.

How are you trying to do this? What happens when you try? Are there any error messages?

One more question in addition to Yer_Man's: You wrote "II have the library backed up on Time Machine and iCloud". How did you back up the library to iCloud? Has the library been syncing with iCloud Photos?

I do want to buy a new external hard drive and have been searching for one that is formatted Mac OS Extended (journal) format. Are external hard drives sold like this or do you have to buy one and format it yourself? If you can buy it, can you help me as to which is the best to buy?

I use Samsung SSDs in the main. You won't be able to purchase a disk formatted Mac OS X Extended, Journaled or apfs, but you can reformat these yourself in seconds, using Disk Utility.

Erase and reformat a storage device in Disk Utility on Mac – Apple Support (UK)

I would suggest using apfs going forward.

What is the name of the template and where did you get it?