Symptoms
When you set the ConnectionLimit property of the SFTP adapter receive or send port to 0 (zero) in Microsoft BizTalk Server 2013 R2 or in Microsoft BizTalk Server 2013, you receive the following error message:
"The Messaging Engine Failed to add a receive location "ReceiveLocationName" with URL "SFTPURL" to the adapter "SFTP". Reason: "System.ApplicationException:Connection pool size is zero.
Note The minimum supported value for ConnectionLimit is 1. A value of 0 is invalid. This fix updates the user interface to require a minimum of 1.
Resolution
Cumulative update information
This problem was first fixed in the following cumulative update for BizTalk Server:
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, 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 Service Pack support.