title: Internal Server Error being returned from ASP.NET MVC Action in Azure App Service Plan
body: <p>I'm hosting an ASP.NET MVC 4.6.2 application in Microsoft Azure in an App Service Plan and using it purely as an API (that is, I'm not using WebAPI but using standard Controllers and Actions as my API for a web UI that lives in a different project).</p>
  
  <p>Everything was working fine until I started getting a generic 500 Internal Server Error returned from one of my Actions (also, all actions are configured to return JSON). Other Actions work fine.</p>
  
  <p>I have Rollbar setup to log all Application exceptions and nothing was being reported.</p>
  
  <p>What was causing this error?</p>