Working with Projects using Project Web Access
Using Project Web Access to check out an enterprise resource generates a temporary project file for Microsoft Project Server. While you can integrate this temporary project file with PPM, once you close this temporary file, the file is not saved on the Microsoft Project Server. Even if you save the temporary project file, it is not saved on the Microsoft Project Server. Therefore, after closing the temporary project file, you cannot open the integrated project file on PPM from Microsoft Project Server because it is associated with a project file that does not exist on Microsoft Project Server.