While working my vacation images this morning, I encountered this message when I tried to create a virtual copy of an image...
I tried closing Lightoom and selecting database backup, but that operation seemed to stall (no progress after several minutes), so I cancelled the backup to let Lightroom close. When I re-opened Lightroom I found that I had lost about an hour's worth of image workflow. Uugh!
How can I ensure I don't lose work again?
Do I need to create a new catalog? Is this one showing signs of an impending crash?
Also, I've been reading online about saving in Lightroom and based on what happened to me today I'd have to take exception with the claim that Lightroom is automatically saving your changes as you work. Clearly, I made multiple changes to no small number of images, and the only time I encountered an error was when I tried to create a virtual copy of an image. Lightroom then allowed me to exit without warning me that workflow changes had not been saved, and when I re-opened Lightroom I found that I had lost over an hour's work in Develop.
Well, it looks like the volume is missing while backing up the Lightroom catalog. You may try changing the location for backup and check if that helps. How to back up catalogs in Lightroom
Where exactly. what volume, is your LR catalog located?
As for the failed backup of the catalog, as stated above it seems the volume, the disk, that is selected as the backup location is not accessible for the backup system to write to the drive.