Data destruction object &1 is already reserved for ILM object &2

What causes this issue?

The assignment of a data destruction object to an ILM object must always
be unique.

System Response

It is not possible to save the registration of data destruction object
&V1& for ILM object &V3&.

How to fix this error?

Remove the reservation of data destruction object &V1& for ILM object
&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.