Restore the catalog from recent backups
As suggested by dj_paige, you can try to restore an old backup.
You can also try to create a new catalog and Import the old catalog into it by following the below link:
Also try to run Lightroom application as an administrator and then try to open the catalog.
I've tried to restore an old backup files, but both(I have 2) are broken.
I've also tried to try to create a new catalog and Import the old catalog into it ...
It still don't work....
Broken? What does that mean in this context?