PROBLEM
When trying to open a catalog, an error message “Unable to Open Catalog. The catalog is currently in use by: ...” appears.
SOLUTION
1. Close Capture One
2. In Finder, locate your catalog file, right-click on it, and select Show Package Contents. In Explorer, just navigate to the catalog folder and click on it to show its contents.
3. As a result, you will see the content of the file package or folder. Delete the writelock file.
What is the writelock file anyway?
When a database is opened, Capture One places a writelock on the entire database to prevent simultaneous changes, which helps avoid conflicts but limits multi‑user access. If you copy a Catalog or Session while it is still open, the writelock file is copied as well, preventing the copy from opening until the original database is properly closed. Deleting the writelock manually while the database is in use can allow multiple users to access it, but this risks database corruption, so only delete it when you have closed Capture One.