SAP Message CAVE005 - Sourcing main item &1 (document &2) was not transferred

Diagnosis The sourcing main item &v1& (document &v2&) was not transferred. A subitem that originated from a rule-based availability check wastransferred. In order to be able to process this item correctly in R/3,the relevant main item is also needed. The main item is missing here inthe transfer. This could be caused by an inconsistency between APO andR/3.