Data model &1: Entity type &2 used as hierarchy node

What causes this issue?

Entity type &V2& is used as a hierarchy node for entity type &V3&.
Therefore, you can only hide both entity type &V2& and entity type &V3&.

System Response

The system does not save the settings.

How to fix this error?

Remove the entry for entity type &V2& or add the entry for entity type
&V3&.

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.