Diagnosis
A serialization error has occurred for the HR object &V1&, which wasreceived from the logical system &V4&.
The expected serialization counter has the value &V2&. However, theserialization counter in the IDoc has the value &V3& and is thereforetoo small.
In spite of serialization, it therefore seems that this IDoc was notposted in the past. Instead, newer IDocs with higher serializationcounter values were posted. However, this should have resulted in aserialization error since there would have been a gap in theserialization counter values.
This inconsistency may be because the serialization counter was changedmanually in the registry of the sending or receiving system.

Procedure
Decide what to do based on your own particular situation. Responsescould range from ignoring or editing the IDoc, to manually adjustingthe serialization counter in the registry of the receiving system tothe expected value.