Down payments exist for document &1 &2

What causes this issue?

Document &V1& comes from SAP Transportation Management (SAP TM).
Financial Accounting has already made down payments of &V3& &V4& for TM
document &V1&, item &V2&.

System Response

The payment program settles the down payments automatically with the
payments to be made.

How to fix this error?

If you want to explicitly allocate a down payment to an invoice, you
must make a manual transfer posting.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.