Can't open backup catalog of LR4 in LcC on new computer

[Valerie_MacPhail1262]

I used Lightroom 4 for years on an old iMac computer.  I couldn't upgrade Lightroom beyond that point because the computer operating system had reached its limit.  I now have a new MacBook Air, and have signed up for a trial subscription to use Lightroom Classic.  My old back up files are all on a Time Machine external drive.  I moved these files from that drive onto the desktop of the new computer: LR4 Catalog-original.lrcat, LR4 Catalog original.lrdata, LR4 Catalog-Previews original.lrdata, and LR4 Catalog-original.lrcat-journal.  I have changed all the permissions on each of them to "read and write", and I changed the permissions for the desktop too.  I've given full access to LrC.  And still I only get this message when I try to open the catalog:  "Lightroom cannot use the catalog named Lightroom 4 catalog-original because it is not writable and cannot be opened."  I don't know what else to try.  

[Rob_Cullen]

"changed the permissions for the desktop too"- Does that mean 'Full Disk Access'?

I am not a Mac person, but might suggest this link-

FULL DISK ACCESS PERMISSIONS

And move the folder of "Lightroom" files off the Desktop to another parent folder like {Pictures}.

[Valerie_MacPhail1262]

Thanks for the suggestions. I had given Full Disk Access, and I just tried moving the Lightroom files to the Pictures folders, but still get the same result.

[JohanElzenga]

The .lrdata "files" are not really files, but so-called 'packages'. A package is a folder that has a special flag, so the Finder treats it as a file. If you change permissions on a package, then you must make sure you also change the permissions of all the contents, not just this wrapper. I'm typing this on my iPad so I cannot check how to do that or show a screenshot, but when you change permissions of a folder, you can click on the three dots and choose 'Apply to Enclosed Items'. I expect that's the same for packages.

Another thing is that you say you moved these files from a Time Machine backup. That might also be the cause of the problem. Ideally you should use Time Machine to do this, not do it manually.

[JohanElzenga]

By the way. The only thing you need is the .lrcat catalog file. All the other files can be rebuilt by Lightroom Classic. Having all these files hanging around -with possibly the wrong permissions- could stop Lightroom Classic from opening the catalog, so try moving (copying) only the catalog file to another folder and try to open it in Lightroom Classic.

[Valerie_MacPhail1262]

I have now tried these things--the only thing in my Lightroom folder within the Pictures folder are the two LR catalogs--my original LR4 catalog, and the new one that Lightroom Classic created when I opened it.  I found one more place to give permission in that folder, but still no success.  Would it be worth trying going back further to older backups of the catalog?  I'm starting to fear that I'll need to import all my old photos, which are in folders by year, and not have any of the organization or edits.  

[DenmarkOne]

When opening an old catalog from within a newer LrC. It usually prompts, asking for permission to upgrade the specific catalog that you are trying to open. Are you allowing it to do so? 

[Valerie_MacPhail1262]

I had read about that happening and was prepared for it, but I have never gotten that request--only the message attached here, which I get every time, no matter what else I've done.

[JohanElzenga]

Open the catalog folder and check if there is a file with the name of the catalog and ".lock" extension. If there is, trash it and then try again. 

[Valerie_MacPhail1262 · Accepted solution]

Thanks to everyone who offered suggestions about opening my old LR4 catalog on my new MacBook Air.  I took all the suggestions about giving permission to the file and to the various layers and folders, and applied that back on the old computer.  I cleared out the folder on the new computer, and then put only the LR catalog in that folder.  When I clicked on it, I finally got a request to upgrade that catalog.  I did so, and it all seems to be working beautifully now.  Thank you!

[JohanElzenga]

Good to hear! From now on, use Lightroom Classic to make regular catalog backup, do not rely on just Time Machine. The reason is two fold. First, when Lightroom Classic makes a catalog backup, it first verifies the integrity of the catalog. Time Macine obviously cannot do that. Second, Lightroom Classic optimizes the catalog after the backup has been made. Again, Time Machine obviously does not do that. Backup to another drive (the default is the catalog folder but that is useless in case of a disk problem). You can select the destination in the backup dialog.