Updated my MacBook Pro to Big Sur bc the LrC updates suddenly made it incompatibale with the older OS. But now that I have the latest updates I find that LrC will not open with any of my existing catalogs. Only if I create a new catalog will it open and run. I have literally 10's of thousands of photos across a multitude of catalogs for this year alone, most of which have gone through my culling and editing workflows, only now I have no access to all that previous work. I worked thhrough many of the discussions here and tried the prescribed fixes, but nothing has worked. So what now?