This issue needs to be investigated by Linda. This is a include file problem.
The Write command calls the Spacecraft::GetGeneratingString. That method correctly creates the generatingString. However, at the end of the method, it does not return generatingString, it returns SpaceObject::GetGeneratingString. This method deliberately CLEARS the generatingString if not created from the main script:
generatingString = "";
("GmatBase::GetGeneratingString() just returning blank, it is not "
"created from the main script\n");