The DNG files contain the sort of information that’s usually contained in a raw file’s XMP sidecar, so that’s normal. Also, in an update of Aperture released a few months or more after I wrote this piece, Apple updated Aperture so that it could read DNG files. I mentioned this in an update but also mentioned that I hadn’t gone back to test it. I’m glad you found that it works! Thanks for commenting.

Bahi

I’ve just plumped for this site, because it’s more likely to viewed here than my own site, and it’s as good as any for what I would like the world to know about how to try and fix light room corruptions.

They happen.

And when they happen, first time, and it cannot be repaired…..you panic….big time.

Don’t.

Do daily backups via lightroom and do keep XML sidecars. Of course have additional backup plans but I’m talking about issues relating to corruption.

O.k. So your catalog is corrupted and LR is unable to repair it. You could go to your day old backup but the problem is that all that work you’ve done today will be lost….and that just makes your Heart sink.

There are a couple of strategies I use to tackle this when it occurs. First is to take a copy of the catalog (usually stored in [your username]/Pictures/Lightroom]) and copy it to another drive.

Then I rename it the catalog – just add 1 to the end or something. Now double click to open (on PC at least).

It will open….hurrah you say…ah but wait….the corruption still exists….you try backing up the catalog it will fail….just rename and reopen again to go back to where we want to be.

O.k. So open, now what?

Well here’s the laborious process…..it takes a good hour or so of your time but it’ll help with ensuring your work from today I’d not all lost.

Right, first thing is to go and select all photos in the catalog. Once done, export the selected photos as a new catalog….put it somewhere meaningful.

If this works then delete all the photos from the catalog (not the originals on disk)….now backup, optimize and test integrity. If it fails then the problem is something other than the photos. If it works, then simply reimport the catalog of photos back into this empty one. Backup to test integrity.

If it fails, then rename, Reopen. Now export out any collections, settings etc that you may have created since yesterday. O.k now get a copy of yesterdays backup and import in both the exporter photos and the settings. That’s it.

Well…unless when you exported the photos LR said it couldn’t because of corruption.

So the problem then is that one or more photo entry in LR, as a database record more than likely, has corrupted. So your job is to find that photo. To do this. Select roughly half of all photos and export. If it exports then problem is with the other half….repeat halving the set each time…..until you find the photo that when exported on it’s own causes a corruption error.

To fix this, the solution I found to work was to right click the photo and open in explorer (or whatever your Mac equivalent is). I then renamed the offending photo by add an x to the end of it’s name. You will now see a ? On the thumbnail of the photo. Click on the photo and LR will ask you to locate it. Locate it as the renamed version and it will open. Repeat this process to rename it back to it’s original name and locate it again. Once done, you should find that you’ve fixed the photo entry that corrupted the catalog. To confirm, backup and test integrity.

If it works, then pat yourself on the back.

Now why xmp sidecars….well they act as backups too.

If you make changes…they will store them as well on LR.

So if comes down to it, you can simply use yesterday’s backup and when you open it, any changed images will be marked with an up arrow. Click on the arrow and it will ask you if you want to use the xmp sidecar data instead of LR’s data. Say yes, and your work will be refreshed and up to date.

That is of course if the files are all raw…ow you will have to reimport non raw in that you created since yesterday.

Ok quite a brain dump….hope this helps someone.

Backup daily. Keep xmp (see preferences).

Thanks.

[Thanks, Mr Sharma. This has the authentic ring of experience to it. Regards, Bahi at Shoot Raw.]

[Bahi replies: As of August 2010, we're not currently running this offer because, in the end, there wasn't enough sustained interest in it from amateurs but if any amateur photographer would like to contact us—perhaps if hoping to turn professional or just trying to improve workflow and post-processing skills—we're happy to try to work something out on price. When writing, just let us know which aspects of Lightroom you need to cover. Thanks for asking, Anna! Since we're in now in touch over e-mail, I won't reply further in these comments but will publish your comment and this response as information for others.]