On the Repository tree view, the red lock appended to the repository item shows that the item is already edited by another user, or, in the case of a business model, is already opened in the Talend Administration Center.
But you can still open and view the locked item in the design workspace in a read-only mode. Right-click the item in the Repository tree view, and then click Open to view the item content.
Alternatively, you can get read-write access to locked items by opening the project in offline mode. For more information, see Accessing items of a remote project in offline mode.