Recently, after updating BizTalk 2013 R2 with Cumulative update package 2 for BizTalk Server 2013 R2 (CU2), the WCF-SAP adapter failed to operate successfully. This is particularly concerning, especially in Production scenarios, when we generally feel comfortable applying CU's. 

You will see an error similar to the following:

System.IO.FileNotFoundException: Could not load file or assembly 'sapnco, Version=3.0.0.42, Culture....

The undocumented issue is that CU2 actually enables BizTalk WCF-SAP adapter, sapBinding, compatibility with the SAP .NET Connector, while creating an additional binary dependency.

Here is more information on article number 3100811.

The SAP .NET Connector 3.0 must be downloaded from the SAP Marketplace and installed on all BizTalk nodes running the WCF-SAP adapter. This functionality can be seen via the sapBinding of the BizTalk WCF-SAP adapter.

It should also be noted that the latest Visual C++ 2010 Redistributable (or sp1) for both x86 and x64 is required for proper functionality. Here are some links:

OR **Phidiax BizTalk 2013 R2 CU2 causes WCF-SAP adapter failure - sapnco - System.IO.FileNotFoundException Could not load file or assembly