When posting the IDOC to SAP through TIBCO ActiveMatrix Adapter for SAP subscription service,  the adapter could auto load the EDI_DD data for each mapped segment if there is no mapping in the EDI_DD fields. But in the following cases user must manually map the SEGNAM in the EDI_DD data.

1. Using tRFC protocol and the segment type starts with a slash. (typically when the IDOC is in a namespace). 
Adapter may not auto load correct SEGNAM definition value if the segment type starts with /, the auto loaded value would later cause a processing error and the service would fail without error notice, the following log will be printed:
Info [Application] AER3-000098 [Thread-4] IDOC RFC Function invoked: IDOC_INBOUND_ASYNCHRONOUS 
Info [Adapter] AER3-000086 [Thread-4] IDOC received in Explode mode tracking=<trackingid>
Info [Adapter] AER3-000135 [Thread-4] Segment name: <segment name that start with a slash> added 
Info [Adapter] AER3-000091 [Thread-4] Total IDOCs processed: 1 tracking=<trackingid>
Note the service stopped before sending the IDOC to the SAP, but the IDOC count message is printed which makes it look like the process completed. If using JMS queue transport,  the message can not get confirmed and thus it will block further new messages. If such error occurs, please needs to remove the pending message in the Queue manually and resend the message with correct mapping on EDI_DD/SEGNAM field.

2. Sending the IDOC in qRFC protocol.
For the instruction of how to fill the SEGNAM type value for qRFC, please refer to Configuration Deployment document chapter 10 - Mapping Data for TIBCO ActiveMatrix Adapter for SAP Services (page 177).