When I start the lightrrom application I receive the following message: the lightroom catalog called "LightroomCatalog" can not be opened because it is already open in another application.
Message was edited by: JSM (Discussion successfully moved from Adobe Creative Cloud to Photoshop Lightroom)
Search for a file with the extension .lock. It will be in the same folder as the LR catalog file. Delete that .lock file then try opening LR.
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