SAP Message USMD1042 - Data model &1, entity type &2: Number of leading entity types is invalid

Diagnosis
For entity types with storage and use type 3 for which the checktable is predefined by the data element or domain, the other key fieldsin the check table must be mapped using relationships with Leading
as the relationship type. The check table for entity type &V2&contains &V3& additional key fields. However, &V4 leading entity typesare defined using relationships.

System Response
The data model cannot be saved or activated.