How To Fix MC714 - Cardinality & of the foreign key &-& is not permitted here

MC714 - Overview

• Message type: E = Error

• Message class: MC - Aggregate: views, matchcodes, lock objects

• Message number: 714

• Message text: Cardinality & of the foreign key &-& is not permitted here

What causes this issue?

For maintenance and help views, there should be exactly one record pf
the dependent base tables for one record of the primary table.
For maintenance views, this is due to the maintenance interface
(transaction SM30).
For help views, this is the only way to uniquely display the records
found.
For this reason, the join conditions may only be derived from the
foreign keys of cardinality 1 or C (with respect to the dependent
tables) for these view types.

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?

Error message extract from SAP system. Copyright SAP SE.

MC714 - Details

• The SAP error message MC714, which states "Cardinality & of the foreign key &-& is not permitted here," typically occurs in the context of data modeling or when working with database tables in SAP. This error is related to the cardinality constraints defined in the data model, particularly when dealing with foreign keys.
  
  Cause:
  The error arises when there is a mismatch in the expected cardinality of a foreign key relationship. Cardinality defines the number of instances of one entity that can or must be associated with each instance of another entity. Common cardinalities include:
  
  One-to-One (1:1)
  One-to-Many (1:N)
  Many-to-One (N:1)
  Many-to-Many (N:M)
  
  The error indicates that the cardinality defined for the foreign key relationship does not align with the data model's expectations or constraints. For example, if a foreign key is defined to allow multiple entries in a table but the corresponding primary key only allows a single entry, this inconsistency will trigger the error.
  
  Solution:
  To resolve