Scenario: Recently we have upgraded our project solution to Visual Studio 2013. Visual Studio 2013 is awesome, specially it’s loading speed. VS 2013 is loading solution file very speedy compare to VS 2010. There are many other eye catching features in VS 2013. But I am not writing this post for it.. as you will find many blogs on VS 2013 features :). Coming back to reason of this post – after upgrading our project to VS 2013, one of our project was not able to load. It was SandCastle Help File Builder project which was now no more supported with VS 2013. I was getting “unsupported project” error message. Reason: “SHFB Visual Studio Extension Package” of Sandcastle Help File Builder 1.9.7 is not supported in Visual Studio 2013. So you need to install “SHFBGuidedInstaller_1980”. How to load Sandcastle Help File Builder project in VS 2013? I found that currently I have installed Sandcastle Help File Builder 1.9.7 on my system which supports VS 2010 very well. But it is not supporting VS 2013, you need to install Sandcastle Help File Builder 1.9.8 to support with VS 2013. So if you are facing simillar situation like me, then go ahead and install version 1.9.8 from below link. https://shfb.codeplex.com/releases/view/105809 Upgrade Visual Studio 2013, Install Sandcastle 1.9.8 !!!