failure in opening Lightroom classic catalog

I too have this issue  I am on Windows 11 and shut down my desk top Saturday Night.  Sunday when I boot up and attempt to launch LRC I get the Failure message.. I followed the notes to delete the Current File.  But still get the error.  Somehow I see that my LRCAT infor might have been copied to Onedrive?  I hate One drive and had that turned off or so I thought.  What do I do?

Call on a LRCAT backup?

Follow @Rob_Cullen's advice.

Also, your MacBook most certainly has a Pictures folder unless you deleted for some reason. Most likely you will find a Lightroom folder with the catalog in the Pictures folder. If you google, how to find the Pictures folder on Mac, you will find lots of tutorials.

Try this, Double click on Mac HD > Users > your user name > Pictures folder should be there.

Catalogs have the file-type of .LRCAT  (Not .LRCAT-DATA)

Search for ???.LRCAT files to open.

Backups will compress the Catalog in a .ZIP file dated with the time of backup. They need to be extracted from the ZIP to allow opening when restoring from a backup catalog.