User is not added to a Post Office via iManager.

You have managed to install GroupWise plugin for iManager and properly configured it. You want to add existing eDir user in a Post Office via iManager - all seems to be working fine but the user never appears in GroupWise system. The same happens when you create a new user and then modify it. You can select a Post Office where the user shall belong to but it never gets created in GroupWise. 

This problem happens when eDir user object does not have First Name field filled in. Once First Name was set, adding user to a specified Post Office succeeded.