SAP Message RH231 - InfoObject & is not entered for & as a foreign hierarchy characteristic

Diagnosis
The InfoObject &V1& has not been entered as an external characteristicfor the hierarchy basis characteristic &V2&. A characteristic can beused as an external characteristic in hierarchies if it has beenentered as an external characteristic in the InfoObject maintenance ofthe hierarchy basis characteristic.

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

Procedure
Select another characteristic or enter the characteristic &V1& as anexternal characteristic in the InfoObject maintenance of characteristic
V2 (infoobject maintenance-> tabpage: hierarchy -> pushbutton:External Characteristics in Hierarchies).