If the RNIF disassembler encounters an error condition when you disassemble an RNIF-formatted message, it generates an error message that's subsequently logged to the event log by the BizTalk runtime. Details about the error, including a specific description of the error condition, aren't written to the event log correctly. After you apply Cumulative Update 1 (CU1) for Microsoft BizTalk Server 2016, the error details will be included in the message that's written to the event log.
Cumulative update information
This problem was fixed in the following cumulative update for BizTalk Server: