Importing originally synchronized projects
When the imported project is named the same as an existing project, but the version number is the same or newer, the newer project version imports if the existing project does not contain any data. Otherwise, when loading an originally synchronized project on top of an existing project, you must first create a deployment package that will move the data from the local computer into a deployment package file (*.dpz). This importation method works only for projects where the project data is on the local system, and the project is originally synchronized.
See