EDIFACT EDI Separator - strange error when more than one message type
I'm currently implementing quite a few EDI interfaces and I've discovered a strange case. By the way, I am using SAP PO (PI with Java stack only) version 7.4 with the B2B adapter. I'm using the EDI separator also described here:
to split a file into multiple EDI message types. It works when I have multiple messages of the same type (for example, multiple ORDERS messages), but it doesn't work when I have two different types of messages (irrespective of the type - ORDERS and ORDRSP, ORDRSP and OSTRPT, ORDERS and INVOIC...), giving me a strange error at the second one saying:
Adapter-Framework: com.sap.aii.adapter.ediseparator.ra.integration.DispatchException: Message cannot be dispatched: Message cannot be dispatched: Error in conversion of INVOIC/98B-Edifact-Document at character 91 to XML: java.lang.UnsupportedOperationException: Cannot find next state and action for current state "B2B,UNH" and segment "UNZ"
This is given always for the second message type found in the file, no matter its message type.
I checked this error message, it is briefly described here: Troubleshooting Information for EDI-XML Converters - Technology Troubleshooting Guide - SCN Wiki
Unfortunately it does not apply to my situation as in my case it is ALWAYS working if the message reportedly having an error is processed separately in one file or the input file only has messages of one type (irrespective of the type).
Attached you will also find the configuration for one integrated configuration and one comm channel. As said, I followed that Inbound step by Step config without significant deviations.
Please let me know if you have any ideas on how to fix this.