SAP Message VL299 - No availability overview for items belonging to project with reservation

Diagnosis
You attempted to display the availability overview manually in deliveryprocessing for an item that was created with reference to a project andwith reservation &v1& &v2&.

System Response
The system does not allow this entry.

Procedure
You can display the availability situation in Shipping->Environment->Lists->Avail. overview.
In deliveries created with reference to reservations, the requirementsremain assigned to the reservations until the GM posting is carriedout. If the delivery quantity of multiple partial deliveries is largerthan the reserved quantity, it is still true in this release that theATP quantity displayed differs from the actual quantity confirmed inthe availability check. The ATP quantity displayed is then too high bythe overdelivery quantity.