You Cannot Invoice Periodic and Interim Billings Together

What causes this issue?

You tried to invoice a periodic billing and an interim billing together,
and are using the 'payment scheme' budget billing procedure.

System Response

The system cancels the invoicing.

How to fix this error?

1. Separate the invoicing units into periodic billing and interim
billing.
2. Use event R540 "Determine Billing Transaction and Document Types for
Open Items" to determine the billing transaction.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.