CppCodeProvider assembly not found error in Visual Web Developer 2010

I opened a website in Visual Web Developer 2010 and at the top of the page there is an error squiggle 开发者_运维知识库on the master page declaration:

<%@ Master Language="C#" AutoEventWireup="true" etc...

The error is "Could not load file or assembly 'CppCodeProvider, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference."

The strange thing is that I'm not using C++ in the website at all. The code-behind is C#.

Can anyone tell me where this assembly is being referenced?

It's possible that your .NET Framework target is pointing to a version other than the project. In VS 2010 Web Developer go to Website -> Start Options -> Build and set the target FW to 2.

I'm not 100% sure this will solve your problem, but it did it for me when I ran into it.