I was working in a Lightroom Catalog and was 3/4 of the way finished editing a wedding when I received the attached error saying that the catalog was somehow corrupt. If this was a portrait session with 30-35 images it wouldn't be the end of the world because I could just start over...but I've spent at least 8 hours on this wedding and I do not want to have to do it all over!
Also, there is not a backup available since I was just working on it today and had not closed the catalog to back it up.
I've tried the following steps to rectify the situation:
If you have no backup of the catalog then in all probability it will be necessary for you to create a new catalog and import the images again. Perhaps it's time to reevaluate your backup strategy. It might be worth your time to backup every time Lightroom closes.