Message SAP WRF_AT159 - The recipient referenced in purchase order &3, item &4 no longer exists

Diagnosis The recipient referenced in purchase order &V3&, item &V4&, no longerexists in allocation table &V1&, item &V2&. System Response The recipient in allocation table &V1&, item &V2& was probably deleted.The reference to the allocation table item in purchase order &V3&, itemV4 no longer exists. Procedure Check allocation table &V1& (transaction code WA02).