title: How do I reference Route and ResponseType Attributes?
body: <p>My computer unexpectedly crashed while I was working in visual studio on a web application. As a result my csproj was completely corrupted, so I had to start a new web project and re-add all the files and assemblies from my old project.</p>
  
  <p>But for some reason Route, which should be in System.Web.Http, and ResponseType, which should be in System.Web.Http.Description cannot be found, even though I still have the appropriate usings for them. Also, my project is still referencing <code>System.Web</code> and <code>System.Web.Http</code>, and all the other stuff in my application seems to not be generating any errors like this at the moment.</p>
  
  <p><a href="https://i.stack.imgur.com/85WwH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/85WwH.png" alt="enter image description here"></a></p>
  
  <p>I've also tried writing out the full path to these classes (i.e. <code>System.Web.Http.Description.ResponseType</code>) but while intellisense is able to explore the namespace, the Route and ResponseType attributes are missing.</p>
  
  <p>I'm not sure if this is related, but when I right-click on Controllers and select Add, I don't get an option to add a controller any more. Something got really messed up with this project...</p>