InfoObject & is not entered for & as a foreign hierarchy characteristic

What causes this issue?

The InfoObject &V1& has not been entered as an external characteristic
for the hierarchy basis characteristic &V2&. A characteristic can be
used as an external characteristic in hierarchies if it has been
entered as an external characteristic in the InfoObject maintenance of
the hierarchy basis characteristic.

System Response

Characteristic &V1& cannot be used to insert characteristic nodes.

How to fix this error?

Select another characteristic or enter the characteristic &V1& as an
external characteristic in the InfoObject maintenance of characteristic
&V2& (InfoObject Maintenance-> Tabpage: <LS>Hierarchy </>-> Pushbutton:
<PF>External Characteristics in Hierarchies</>).

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.