Implementation of callback method &3 is missing for ILM object &1

What causes this issue?

System Response

The rule for ILM object &v1& cannot be determined because the
corresponding implementation of the callback method does not exist:
Interface:,,&v4&
Class:,,&V2&
Method:,,&v3&

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?

Implement the missing callback method.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.