Photos Libraries do not open, Error 4302

Lets recap the current status:

I've been getting error 4302 on opening my photos library. Recently that changed to error 5416.

My photos library is on an external drive (M2, APFS (Encrypted), connected via Thunderbolt), and it is not currupted. Its size is 1.7 TB (huge, I know) but the problem occurs also with a smaller library with about 50 GB size, so not the cause.

• Rebooting solves the problem temporarily, after a fresh reboot of OSX, Photos opens the library just fine, but the problem reoccurs after a while (not sure what the causal action might be... maybe sleep mode?)
• Remounting the external drive does NOT help.
• Repairing the library does NOT help.
• Repairing the library on a non-M1 Mac, running Monterey didn't solve the problem.
• Problem occurs with different cables, so not the connection.
• "Ignore ownership..." has always been set correctly.
• Reformatting to Mac OS Journaled wasn't an option - but the smaller library with the same problem is on such a drive, and shows the same problem.

This stinks like a Photos bug, not like a library corruption (multiple affected, but both in good condition and in principle working fine).

Hi Justin, thank you for your reply.

Unfortunately, "Ignore Ownership on this Volume" was already checked, so that is not the cause of the problem.

In the meantime, I did the following things, all unsuccessfully:

• Repair the library: did not help, but lost me almost all face recognition data on 330k Photos (Thanks for nothing, Apple)
• Ran First Aid in Disk Utility on the Partition, the Container and the Physical Drive (don't know whether this actually makes a difference. Did not help.

The disk was freshly formatted for use as my archive.

I'm currently in contact with Apple Support, but I'll keep updating this here, so people with similar problems might find the info.

Suggestions by the Apple Support were:

• Repair the library on a non-M1 Mac, running Monterey. Did that, but it didn't solve the problem.
• Reformat the external drive (currently APFS) to Mac OS Extended (Journaled). Currently in the process, takes a while to move the data.

While moving the data, I took a backup of my library I had from before the Ventura update, and opened it up in Ventura. Photos did the usual Updating (whatever is done in that process...) and lo and behold: The library opens fine just after updating, but throws an error 5416 once it is closed and opened again. Rebooting has the same effect: works fine again. So basically the same behavior, this time with an error code 5416 instead of 4302.

Thanks for your thoughts on my problem. A few notes:

• I also get the problem on that smaller, different library - which is stored in a Mac OS Journaled formatted (end therefore unencrypted) drive.
• I've been running my main library from an encrypted drive for years. The problem turned up only when I updated to Ventura. Whether that's coincidence or causality I don't know - but if photos all of a sudden wouldn't work with Apple's own drive encryption any more, that would be weird. Or a bug.
• Again: the library works JUST FINE, but only half the time. ALWAYS, if I just rebooted the Macbook. So it is very unlikely damaged files within the library. Scanning the originals within the library package with Bad Peggy right now, anyhow: so far it only comes up with files exclusively from an old mobile that are probably badly encoded from the start (and have been in the library for years).

My takeaway so far:

• It's not the original image files in the library (because it works fine half the time, and Bad Peggy doesn't show conclusive errors)
• It's not the library database (because it works fine half the time)
• It may be related to the encryption? (but why would it work fine half the time? worked fine with encryption for years...)
• It may be related to changes made to Apple Photos in the Ventura update (because of the timing of the problem occuring)

I'm going to try setting up another Mac OS Journaled drive with the data... will take some time though.

Update:

The last technician apparently wasn't too well versed in Apple tech and sent me on a wild goose chase:

Being irritated that I had my external drive formatted as APFS (encrypted) he suggested trying out Mac OS Extended (Journaled). Turns out: If you want to have an encrypted drive, OSX reformats an Mac OS Extended drive to APFS automatically. And having a photo archive on an unencrypted external drive is... pointless.

Anyhow, after that, OSX Ventura wasn't able to copy my library onto the freshly formatted drive any more: it copied the library database and thumbnails, but not the original photos, copying threw an error after a while, saying that the file was already in place (both using Finder and PathFinder, same problem). I could only restore it to the drive using Carbon Copy Cloner.

Never been this annoyed by this incompetent service and software performance.