title: how to run multiple projects in visual studio simultaneously
body: <p>I am trying to get my main project and my API to run along side each other in Visual Studio 2015. The method that usually works is: start my main project, then right-click on API project, go to Debug, select Start New Instance. But that doesn't always work. It sometimes crashes on me with an exception saying: "Value cannot be null. Parameter name: httpContext".</p>
  
  <p>What is the proper procedure for running more than one project at once from the same Visual Studio instance?</p>