I got the " The Lightroom catalog is corrupted and cannot be used until it is repaired" message. After the repair the catalog was still obviously corrupted. For instance, there are 4800 images in the catalog but it only sees 900. So I have good backups and I brought my latest back up catalog into the folder and it too was instantly corrupted. So I copied the good catalog to just outside the folder with the corrupted catalog and all the image files. I opened this copy of the catalog and connected the images back to it. It is now working normally. My question is-what do I need to delete from the old catalogs before I can move the good catalog back into its proper home?
So I have good backups and I brought my latest back up catalog into the folder and it too was instantly corrupted.
Hard disk malfunction. Maybe a bad sector that includes the folder where your catalog is located. My first advice is always exactly what you did: Unzip another copy of the backup catalog, put it somewhere else on your hard disk (different folder) and then try opening it.
Thanks for the quick reply. Yes I wondered about that possibility. I've now moved both the image file folder and the catalog folder to another drive and the open normally. But I would like to move the catalog back into its proper home. Should I delete the old corrupted catalogs first? And any other files or folders?