Symptoms
Assume that you are using Microsoft BizTalk Server. When an XML message is sent to Multi-purpose Internet Mail Extensions (MIME) encoder, the byte order mark (BOM) isn't removed by the MIME encoder if Content-Transfer-Encoding is 8-bit. In this situation, you may receive the following message, in which BOM characters aren't removed:
A service document ID acquisition error of contents was detected by receive processing of RosettaNet Error message ="Content isn't allowed in prolog."
Resolution
This issue is fixed in the following cumulative updates for BizTalk Server:
Cumulative Update 2 for BizTalk Server 2016
Cumulative Update 6 for BizTalk Server 2013 R2
Note You have to set the PreserveBOM pipeline configuration property to FALSE.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
For information about the service packs and cumulative update list for BizTalk Server, click the following article number to view the article in the Microsoft Knowledge Base:
2555976 Service pack and cumulative update list for BizTalk Server
For more information about BizTalk Server hotfixes, click the following article number to view the article in the Microsoft Knowledge Base:
2003907 Information about BizTalk hotfixes and Service Pack support