Changing the BU of a user using the SetBusinessSystemUserRequest request

Hi All,

I am trying to change the BU of a user using the SetBusinessSystemUserRequest request from a plugin. Below is how I create the request -

SetBusinessSystemUserRequest request = newSetBusinessSystemUserRequest();

request.BusinessId = _tempBU.Id;

request.UserId = userRecordId;

request.ReassignPrincipal = newEntityReference("systemuser", userRecordId);

SetBusinessSystemUserResponse response = (SetBusinessSystemUserResponse)service.Execute(request);

How ever it is throwing an exception. Please help.

Thank You

Best Regards

Sid