You can restore an association between a Microsoft Project file and a Project Management project if an association has been removed or has unexpectedly been removed. Associations cannot be restored if an association never existed between a Microsoft Project file and a Project Management project. Instead, send the Microsoft Project file to a Project Management project (see Sending a Microsoft Project Work Plan to Project Management).
To restore an association:
Open the project in Microsoft Project.
Select PPM > Project Details.
The Project and Portfolio Management Center Integration Details dialog box opens. The fields in the dialog are empty.
Click Restore Association.
Information about the associated Project Management work plan appears in the dialog fields.
URL of the PPM Server.
Username used to log in to the PPM Server.
Name of the Project Management project.
Synchronization mode of the Project Management project.