Exception: Error in message header mapping; agent class is CL_BUPA_ERP_REPL_IPA

Hi C4C Experts,

We're encountering below error during master data replication from ERP using PI. We are simply using the standard mappings from ESR content.

<ERROR_TEXT>Exception: Error in message header mapping; agent class is CL_BUPA_ERP_REPL_IPA</ERROR_TEXT>

The weird thing is that our Employee replication is working perfectly fine but the rest of the master data (debmas, matmas, etc.) are failing due to this error in C4C.

Saw some relevant contents here in SCN but nothing really solves our issue.

Appreciate any helpful insights regarding this matter.

Thank you in advance.

Mark