If the LWF engine returns this error on DWFJobInitiate, you must have specified in the LWF Architect / process definition that this "Manager of Employee" is related to the process or the first activity. Maybe as a jobowner, or as a potential activity owner, or perhaps this manager should receive an email, or this manager is part of the team that may support during the first activity, etc.
It appears that the relation document in the Organisation database is looking for the Manager of your "admin" user in any of the "departments" and probably you did not list your "admin" as member of any department and LWF cannot resolve the @Relation......
Oscar W. Henneken,
Cynapps Workflow Solutions