I use an iMac and LR Classic CC. I thought I was deleting old backup files. But, next time I launched Lightroom Classic CC, I got the message that LR could not find the catalog file. So, I'm thinking I must have unintentionally deleted the main .lrcat file where I catalog most of my photos. I think I emptied the Trash after doing those deletions.
I navigated to where the backups were located and can find some older versions of that catalog but the latest photos are from months ago and for some reason, LR can't seem to find some of the photos (Exclamation Point in upper right corner).
I've also looked in Time Machine but haven't located the catalog file.
Is there any hope of finding or restoring the apparently deleted .lrcat file?
Or do I have to start over, import all my stored photos, re-process them, add keywords, etc, etc.?
Did you look in the Trash can?
If you don't have recent backups ... then you need to change your backup strategy to make regular and automated backups of your catalog file and your photos. No excuses.
You can restore the most recent backup that you have, so you won't be starting from scratch on the photos in that backup. But for newer photos you will have to import them and add metadata and edits.
If you have emptied the trash bin, the only way to recover any deleted file is to use an "undelete" program, of which there should be many available for download off the internet. Being a Windows user, I have no recommendations for the Mac.
Be warned, adding more files to the hard drive, like downloading and installing programs, runs the risk of overwriting the files you want to recover.