I've seen some chats about the same problem, but it didn't help me so far.
I can't open my last catalog (from yesterday) using Lightroom 5 (creative cloud) on Mac, the message is "unexpected error opening catalog".
-> My mac: MacBook Pro (Retina, 15-inch, Early 2013) - OS X EL CAPTAIN Version 10.11.3
-> Catalog location: Samsung External Drive M3 Portable 1TB (new, 1-2 months)
-> Catalog size: 611,2 MB - last save yesterday, March,28th 1:54pm (brazilian time)
What I've already tried after google and adobe forums researches:
:: Find .lock file = not found, anywhere
:: Creating new catalog = no problem with that
:: Open the issued catalog after creating a new one on lightroom = Doesn`t work, same message
:: Re-install the lightroom (creative cloud) = done, but still didn't solve the problem
:: Open catalog of the latest backup (March,21st) = OK with that.
I am very worried and sad , since I've edited a lot of photos for 4 clients/jobs since my last back up on March, 21h unfortunately. Several hours and days working on that. Please I would kindly appreciate an urgent reply!
Thanks a lot in advance and kind regards,
Would suggest you to go to File > Import from another catalog in the New Catalog that you created and test if you are able to import it.
If that does not work, it means that the catalog is corrupted.