Create Controller: "there was a problem getting an appdomain to run the transformation.."

I just set up VS 2013, and was following the steps in the tutorial:http://www.asp.net/web-api/overview/creating-web-apis/creating-a-web-api-that-supports-crud-operations I'm currently facing an issue while trying to create the "ProductsController" controller.
The error message I get in a pop up is given below: (screenshot: http://screencast.com/t/BtaCVXPl) "there was a problem getting an appdomain to run the transformation from the host"
Any idea why this may be happening?