This morning I was working on Lightroom 5 when it shutdown unexpectedly. When I restarted Lightroom a message read that the catalogue I was working on was no longer available. I looked in 'Open Recent' and couldn't find the catalogue (previous catalogues were available but not the most recent one I was working on). I then went to the folder source in 'Finder' (I use a Mac) and the entire folder containing the catalogue and catalogue backups had disappeared (the folder [before it disappeared] had been on my MacBook Pro's hard drive, not an external hard drive). I'm at a complete loss at what happened.
If anyone has experienced this before and/or has any advice on how I can retrieve the catalogue I would really appreciate it! I had 2 months of editing on that Catalogue so am very concerned right now.
Lightroom never deletes the catalog itself.
Go to File menu in Lightroom > Open Recent > open the listed catalogs one by one and check if it contains the one on which you were working.
Where was the catalog stored?
By default, it is stored under Pictures\Lightroom folder and the backup folder also resides within same Lightroom folder.
Did your Mac also shut down or just LR?
Do a search of your drive for .lrcat and see if it is someplace else than you thought.