How to copy a relationship between two projects

I am trying to reconcile an ERD with the reverse engineered database.
I have two projects, one with my ERD definition (p1) and another one that contains the reverse engineered database ERD (p2).
The reverse engineered project has a foreign key relationship I would like to copy in the project containing the ERD (copy FK from p2 to p1).

I have tried to use the ‘Copy within VP…’ but it does not seem to work.
Both tables involved in the FK are in both projects (I have copied them using the function above).

Any way I can do this?


My environment: VP-UML SE 10.2 (20130705) on Mac OS X Lion 10.7.5 (11G63)