So after fooling with that, I ran a check disk on the drive that houses my catalog and it found some errors and corrected them. Sadly when trying to open the catalog, I get the same errors. It encounters a problem and then fails to repair the catalog. This happens to the original and the backup.
The catalogs are probably corrupted by these disk errors, and can't be used. Did you keep your backups on the same disk as the working catalog?
Sadly, yes. I thought I was putting them on a separate disk, but the most recent ones where on the same disk. I just found a January backup on a different drive that Lightroom was able to repair and I found a few corrupt original files... but I see what you're saying. If the corruption was in the catalog files, then I might be ultimately at a loss.
Im having the same issue sadly.