Cannot Restore Photos Library From Backup

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Level 1

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Cannot Restore Photos Library From Backup

When attempting to restore a Photos library from a Time Machine backup, the restoration sticks in "Preparing to copy". I've let this run overnight and it still didn't restore. The backup was done in Big Sur. I recently reverted back to Catalina (to install Boot Camp). I have now re upgraded to Big Sur and receive a message saying "Photos was unable to open the library" when opening photos. I'm hoping the Time Machine backup library will open but I can't get it restored.

iMac Line (2012 and Later)

Posted on Sep 3, 2021 4:00 AM

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Answer 1

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slicksleeve Author

Level 1

5 points

Sep 3, 2021 9:41 AM in response to slicksleeve

I was able to fix the library instead of restoring the backup.

I think the problem was that I opened the Photos library in Catalina and it wasn't recognizable in Big Sur. The backup was only a few days newer than the library on the computer. Thanks for everyones input.

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Answer 2

Old Toad

Level 10

210,497 points

Sep 3, 2021 9:33 AM in response to slicksleeve

If the library was created and backed up in Big Sur and you restore it to Catalina you won't be able to open and use the library. Photos libraries are not backward compatible with Photos versions.

So unless you have a Catalina Photos library backed up with Time Machine that you can restore you won't be able to use it with the Catalina Photos app.

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Answer 3

Sep 3, 2021 9:27 AM in response to slicksleeve

How big is the library?

If it is very large, it may well take a long time for the prepare to copy, and for the copy. There is a lot of processing to do in time machine due to the fact it is an incremental backup system, and the whole library has to be pieced back together from all the different backup times.

Just let it run.

Oh - and where is your library stored. if it is on an external drive that is not APFS, or MacOS extended, then that is why it won't open - and you'll need to copy it to an appropriately formatted volume. In fact if you are trying to restore to an external volume with an incorrect format, that may also be a reason for the restore to fail.

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