A checked out project is copied to user's workspace and becomes available for selection in rule editor. Only checked out projects can be modified. To apply changes made to a project, the project must be checked in as described in Checking In a Project.
To check out a project, in the project tree, select the project and, in the right pane, click Check Out.
The latest project version is checked out even if the user previously opened an older project version.
Alternatively, an opened project can be checked out directly from rule editor as described in Checking Out and Checking In a Project.