SAP Message BILL_ACC_IF007 - No main/sub-transaction is defined in FI-CA for document type &1

Diagnosis It is not possible to process the billing document, as no main or sub-transaction could be determined for posting the billing document inFI-CA, for billing document &V1& in application &V2&. Procedure Check the assignment of the billing document types to main /sub-transactions in FI-CA in the IMG.