I have Windows and used light room a few weeks ago with no problem. Tried to open today and keep getting Microsoft one drive pop up it says "deleted files are removed everywhere" it says recenlty deleted: lightroom catalog. Ircat-shm. I haven't deleted anything. It does give me the option to open one drive recycle and restore deleted files. I tried that but LRC still will not open. It does show that it is running in my task manager. Any one have any suggestions how to fix this?
There are many issues reported here when using Lightroom catalogs with One Drive.
The key files that need to be in the catalog folder for it to work, are the .lrcat and the .lrcat-data files. It'll be faster if the Previews (the .lrdata file/folder) is there, but it's not essential. Other files, like the .lrcat-shm are there when the catalog is open. The .lock file can prevent lightroom opening with a 'catalog in use' error. If you're worried about backup, send the lightroom catalog backup to OneDrive, but keep the main catalog out of it.
Sean McCormack. Author of 'Essential Development 3'. Magazine Writer. Former Official Fuji X-Photographer.