SAP Message V1857 - Item &1 has already been billed. Header data was not copied

Diagnosis
You have changed the pricing date or the exchange rate at header level,and the system has determined that quantities for item &V1& havealready been billed.

Note
The system does not copy the pricing date or exchange rate to itemsthat have already been billed. If necessary, you will need to changethe item manually.
The data is copied to items that have not been billed, if these agreedwith the header before it was changed.

160208Field transport into items already invoiced