I cant open lightroom classic because I keep getting this message. The lightroom catalogue named "lightroom Catalogue" cant be opened because another application has it opened, quit other copy of lightroom before trying to launch. I dont have anything open.
When Lightroom is running, there is a lock file present in the same folder as the catalog. Its purpose is to prevent other users from accessing the catalog. The lock file will be deleted when Lightroom is closed, but if it wasn't closed down properly (crash, power failure), the lock file might not be deleted, and you'll get that error message.
The solution is to delete the lock file manually.
With the Windows File Explorer or Mac Finder, go to the folder that contains your catalog. (usually a folder inside your Pictures folder) The lock file will have the same name as your catalog, and the extension .lock
Delete the lock file. Do not delete anything else.
Note to moderator: Please move to Lightroom Classic