Recently I was deploying a Windows Service that uses SAP .NET Connector 3.0 on a fresh install of Windows (the specific version isn’t important, but it was Windows Server 2003).  I built my installer package, installed .NET Framework 4, and installed my program.  When it came time to execute my service, I received the following error message.

System.TypeInitializationException: The type initializer for
  'SAP.Middleware.Connector.RfcServerManager' threw an exception.
  ---> System.TypeInitializationException: The type initializer for
  'SAP.Middleware.Connector.RfcConfigParameters' threw an exception.
  ---> System.IO.FileNotFoundException: Could not load file or
  assembly 'sapnco_utils.dll' or one of its dependencies.
  The specified module could not be found.
at SAP.Middleware.Connector.RfcConfigParameters..cctor()
--- End of inner exception stack trace ---
at SAP.Middleware.Connector.RfcConfigParameters.Initialize()
at SAP.Middleware.Connector.RfcServerManager..cctor()
--- End of inner exception stack trace ---
at SAP.Middleware.Connector.RfcServerManager
.GetServer(String serverName, Type[] rfcFunctionHandlers)
at DataXstream.AwesomeProduct.InitializeSap()

What was really confounding was that the Fusion Log reported no .NET binding errors! So, what was going on?

Missing Prerequisite!

It turns out that I was missing a prerequisite.  In addition to .NET Framework 4, SAP .NET Connector (NCo) 3.0 Microsoft Visual C++ 2010 Redistributable Package (mscvp100.dll, mscvr100.dll).  After I installed it, everything ran like a champ!  I was a little miffed that the OSS Note I was using as my guide (856863) made no mention of the Microsoft Visual C++ 2010 prerequisite.  So, for all of you that may have similar issues, here is a comprehensive installable prerequisite list (with links!) for the SAP .NET Connector (NCo) 3.0 separated by your program’s target processor architecture and .NET version:

NCo 3.0 32-bit (x86), .NET 2.0 (also 3.0, and/or 3.5)

• .NET Framework 2.0 or .NET Framework 3.0 or .NET Framework 3.5
• Microsoft Visual C++ 2008 Redistributable Pack (x86) (mscvp80.dll)

NCo 3.0 64-bit (x64), .NET 2.0 (also 3.0, and/or 3.5)

• .NET Framework 2.0 or .NET Framework 3.0 or .NET Framework 3.5
• Microsoft Visual C++ 2008 Redistributable Pack (x64) (mscvp80.dll)

NCo 3.0 32-bit (x86), .NET 4.0

• .NET Framework 4.0 (Full Package)
• Microsoft Visual C++ 2010 Redistributable Pack (x86) (mscvp100.dll)

NCo 3.0 64-bit (x64), .NET 4.0

• .NET Framework 4.0 (Full Package)
• Microsoft Visual C++ 2010 Redistributable Pack (x64) (mscvp100.dll)

One More Thing!

It is important to understand the relationship between your .NET project’s target platform and the prerequisites.  The 64-bit version of the Microsoft Visual C++ 2010 Restributable Pack will not work if your project’s target is for a 32-bit architecture.  Be mindful to match the project platform to the prerequisite.