title: Error in project - Uncaught ReferenceError: Raven is not defined
body: <p>I've started getting an error in chrome console <code>Uncaught ReferenceError: Raven is not defined</code>. I have no idea what it is referring to or where it came from. The error doesn't appear when I open the project in fireFox. Can someone shed some light on this?</p>
  
  <p>Error:  <code>Message</code></p>
  
  <pre><code>    Uncaught ReferenceError: Raven is not defined
          at HTMLDocument.&lt;anonymous&gt; (sidekick.js:1)
          at f (extension-lib.js:1)
          at Object.fireWith [as resolveWith] (extension-lib.js:1)
          at Function.ready (extension-lib.js:1)
          at HTMLDocument.xe (extension-lib.js:1)
      (anonymous) @   sidekick.js:1
      f   @   extension-lib.js:1
      fireWith    @   extension-lib.js:1
      ready   @   extension-lib.js:1
      xe  @   extension-lib.js:1
  </code></pre>