title: Referencing a 4.0 C# dll from a managed C++ dll
body: <p>I've got a DLL in C# that targets the 4.0 framework.  I have a managed C++ dll that also targets the 4.0 framework, but when I try to add my C# dll as a reference, I get 'Could not add a reference to file MyFile.dll because it is neither a .NET assembly nor a registered ActiveX control'.</p>
  
  <p>This works fine if both DLL's target 4.5.  I am using VS2012.
  I want to be able to target 4.0 though, not 4.5.</p>