create new site and contact relationship using customer FBDI

Summary:

IS it possible to create a new party site and then create a relationship for an existing contact?

Content (please ensure you mask any confidential information):

I am trying to create a new party site and create relationship for existing contact to this site in single run.

First I tried creating just a new site and that works. Now I am trying to create both in single load.

Getting error for the relationship "The reference to the source system is invalid"

Version (include the version you are using, if applicable):

26A

Code Snippet (add any code snippets that support your topic, if applicable):