The object set could not be saved

What causes this issue?

The TADIR and Object selection is empty

System Response

The object set could not be saved

How to fix this error?

Fill in at least one field in the TADIR or object selection. For the
extended program selection you must tick the <ZK>Activate Selection
</> check box and fill in at least one of the fields <ZK>Program Name
</> or <ZK>Created by</>.

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.