SAP Message AJ799 - Billing document missing for secondary installation &1

Diagnosis
Billing documents from secondary installation &V1& are required forbilling primary installation &V2&. Billing documents must be availablefor the complete billing period of the primary installation. However,there is no suitable billing document in the period &v3& to &v4&.

System Response
The billing procedure for primary installation &v2& is cancelled.

Procedure
Find out why the billing document is not available.