When you use the SFTP adapter to receive messages on Microsoft BizTalk Server 2013, the message that you receive is zero length, but the file name is correct.
When you use the SFTP adapter to send a zero-length message to an SFTP server on BizTalk Server 2013, the message is discarded and nothing is written to the SFTP server.
Note This issue occurs in both BizTalk Server 2013 and BizTalk Server 2013 R2.
Cumulative update information
This issue was first fixed in the following cumulative update of BizTalk Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For information about the service packs and cumulative update list for BizTalk Server, see KB 2555976: Service pack and cumulative update list for BizTalk Server.
For more information about BizTalk Server hotfixes, see KB 2003907: Information about BizTalk hotfixes and cumulative update support.