Cannot post freight settlement doc &1; no charges in freight order &2

What causes this issue?

You tried to post freight settlement document &v1&. The freight order
&v2& on which the freight settlement document is based has already been
invoiced and therefore contains no charges. You can save the freight
settlement document, but you cannot start the process of posting.

System Response

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

How to fix this error?

You must remove the freight order from the freight settlement document
or manually add charges to the freight order.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.