Pipeline material & has no fixed vendor

What causes this issue?

The system could not find a fixed vendor for the
<GL:pipeline_material>pipeline material</>. However, a fixed vendor
is required for determination of the pipeline price.

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?

INCLUDE NA_EINGABE_PRUEFEN
If your entries are correct, create a pipeline material info record
using the purchasing menu, in order to define the pipeline price. Then
enter the goods movement again.
<DS:TRAN.ME11>Proceed</>

Error message extract from SAP system. Copyright SAP SE.