Diagnosis
You attempted to perform billing for a billing order using the
Create Manual Billing transaction (EA16). However,there is already a billing document in the system with the specified enddate that was generated automatically. This means saving the documentcreated manually would lead to inconsistent data.

System Response
You cannot save the document.

Procedure
Change the end date for the billing document. Alternatively, you canalso create a billing document without reference to a billing order.