Empty correspondence entry saved to history

What causes this issue?

A blank entry was written in the correspondence history.

System Response

Correspondence was to be created. However, no data could be found to
enter in the correspondence. Because the periods for this type of
correspondence are guaranteed to be updated in an unbroken manner, a
blank entry in the correspondence history means that no documents were
sent for this period. However, the period was to still found to be in
order.

How to fix this error?

No further activites necessary. There were no errors in processing.

Error message extract from SAP system. Copyright SAP SE.