What causes this issue?

You have tried to assign a unique regulatory list revision, but
identical descriptions exist for different regulatory list revisions
that have, for example, only a different revision date or status. In
such a case, it is not sufficient to enter the description manually, or
to use one of the value suggestions.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

INCLUDE EHPRC_FMD_NA_STOPPROCESS OBJECT DOKU ID TX

How to fix this error?

Use the input help <EX>(F4)</> of the <LS>Assigned Revision </>field to
search for a unique revision.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.