It’s pretty unlikely that you’ll have a major problem with your Lightroom catalog (after all these years of using Lightroom, it’s only happened to me once), and if it does happen, chances are Lightroom can repair itself (which is pretty handy). However, the chances of your hard drive crashing, or your computer dying, or getting stolen (with the only copy of your catalog on it) are much higher. Here’s how to deal with both of these potential disasters in advance, and what to do if the big potty hits the air circulation device:
If you launch Lightroom and you get a warning dialog like you see here (at top), then go ahead and give Lightroom a chance to fix itself by clicking the Repair Catalog button. Chances are pretty likely it’ll fix the catalog and then you’re all set. However, if Lightroom can’t fix the catalog, you’ll see the bottom warning dialog instead, letting you know that your catalog is so corrupt it can’t fix it. If that’s the case, it’s time to go get your backup copy of your catalog (ya know, the one we talked about a couple pages ago).
Now, as long as you’ve backed up your catalog, you can just go restore that back-up catalog, and you’re back in business (just understand that if the last time you backed up your catalog was three weeks ago, every-thing you’ve done in Lightroom since then will be gone. That’s why it’s so important to back up your catalog fairly often, and if you’re doing client work, you should back up daily). Luckily, restoring from a backup catalog is easy. First, go to your backup hard drive (remember, your backup catalog should be saved to a separate hard drive. That way, if your computer crashes, your backup doesn’t crash along with it), and locate the folder where you save your Lightroom catalog backups (they’re saved in folders by date, so double-click on the folder with the most current date), and inside you’ll see your backup catalog (as seen here).
Next, go and find the corrupt Lightroom 3 catalog on your computer (on my computer, it’s in my Lightroom folder that’s in my Pictures folder), and delete that file (drag it into the Trash on a Mac, or into the Recycle Bin on a PC). Now, drag-and-drop your backup catalog file into the folder on your computer where your corrupt file used to be (before you deleted it).
The final step is simply to open this new catalog in Lightroom 3 by going under the File menu and choosing Open Catalog. Now, go to where you placed that backup copy of your catalog (on your computer), find that backup file, click on it, then click OK, and everything is back the way it was (again, provided you backed up your catalog recently. If not, it’s back to what your catalog looked like the last time you backed it up). By the way, it even remembers where your photos are stored (but if for some strange reason it doesn’t, go back to the last project to relink them).