&4 Existing assignment cannot be overwritten

What causes this issue?

The system cannot overwrite the reference assignment for the combination
of material &V1& and plant &V2&according to the general settings for
multiple references.

System Response

The system cannot process this combination during the automatic
assignment of references.

How to fix this error?

If you want to change the existing reference assignment, use the dialog
program <LS>References for Materials without History</>.

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.