P: After the new version "update” today — “Unexpected error opening catalog.”

This thread was closed, not sure why. This is the additional info I was trying to add. 

You opened Lightroom (even though unsuccessfully) , that caused writes to the drive. 

I misunderstood. I thought you could start Lightroom but just not import the wedding photos. 

If you can't even start Lightroom then that catalog is unrecoverably corrupt *1. A couple things to try which probably won't help but won't hurt:

1. reset the preferences file, Rikk posted how to do this.
2. purge the cache by manually deleting all the files in the cache folder. Consider copying them somewhere else first. 
3. same for the Smart Previews folder

*1 Adobe uses a SQL system for the catalog, a search will find the specific product. Try searching forums for that product to see if there's a recovery tool. However don't expect a tool like that to be free or easy to use.

This thread is being merged into an authoritative thread for better tracking and response. 

This thread is being merged into an authoritative thread for better tracking and response. 

Nothing was written onto it. It was not touched since I formatted it. How do I do that if it won’t open the catalog? I have the raws still in just trying to be able to use my catalog again. Is that possible? I truly appreciate your help!!!

That only works if absolutely nothing has been written to the disk since the data loss. 

When a file is deleted, only a single bit is flipped in the file system, nothing is actually deleted but the space is now available for reuse. So Delete a file and then run Wondershare and the file will be recovered. It will find the root of each deleted file, follow the links to each segment and then flip the bit back.

However if after the delete and before running Wondershare, anything is written to the drive then one or more of those recovered files has been corrupted and is gone forever. 

You have a couple of options to identify the corrupt files. 

1. Import images in small batches and with each successful import, exit Lightroom so that the updated catalog will be saved. When a batch won't import, somewhere in that batch is/are corrupted image(s). Split the batch and iterate the process. 
2. Use Preview to step through the images one at a time. 

Wondershare recoverit 

Lightroom classic up to date 

Mac Big Sur (updated to this yesterday) 

1. How did you recover if your backups were gone?
2. What OS? 
3. Which Lightroom product and version? 

I was trying to reinstall an new external and accidentally formatted the wrong external, so the one with my catalog and backups was completely cleared. I was able to recover but now Lightroom won’t open the catalog or backups - saying “unexpected error opening catalog”. I also did the update on my computer and Lightroom yesterday so not sure if that has anything to do with it. I am in complete panic and would appreciate any help! 

Same issue since recent update to new LR - Running mac mojave - imac retina 4k 21.5in 2017

Same problem for me. Uninstalled the LRC10 and installed the previous version 9.4 and everything works fine