Open item in BSEG, missing in BSID (but available in BSAD)

What causes this issue?

There are open line items in table BSEG which are <ZH>not</> available
in the index table BSID but these open line items are already available
in the index table BSAD.

System Response

The system informs about this inconsistency which must be corrected in
your productive system before starting the data migration.

How to fix this error?

For more information, see
<DS:URLA.HTTPS://LAUNCHPAD.SUPPORT.SAP.COM/#/NOTES/2714344>SAP Note
2714344.</>

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.