title: No PDFJS.workerSrc specified
body: <p>Trying to use PDF JS in a local Apache server and receiving the following error in console:</p>
  
  <pre><code>Uncaught Error: No PDFJS.workerSrc specified
  </code></pre>
  
  <p>This is very weird, because I'm following all that the examples specifies here <a href="http://mozilla.github.io/pdf.js/examples/">http://mozilla.github.io/pdf.js/examples/</a>.</p>
  
  <p>I have, in my main folder, a sample file called <code>file.pdf</code> and I'm just trying to display it. I did it by using a iframe with a <code>file</code> parameter:</p>
  
  <pre><code>&lt;iframe src="./web/viewer.html?file=http://localhost:99/PDF/arquivo.pdf" width="1800px" height="900px" /&gt;
  </code></pre>
  
  <p>And now I'm trying to use the JavaScript API to display it. I'm trying to do:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;script src="./build/pdf.js" type="text/javascript"&gt;&lt;/script&gt;       
          &lt;script type="text/javascript"&gt;
              PDFJS.getDocument('arquivo.pdf').then(function(pdf) {
                  // Here I use it
              })
          &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>If I try to include <code>pdf.worker.js</code> manually, I receive:</p>
  
  <pre><code>GET http://localhost:99/PDF/build/pdf.worker.worker.js 404 (Not Found)
  </code></pre>
  
  <p>because it programmatically includes <strong>pdf.worker.js</strong>.</p>
  
  <p>With the sample code I posted here, I receive a log and an error:</p>
  
  <pre><code>Error: No PDFJS.workerSrc specified pdf.js:249
      at error (http://localhost:99/PDF/build/pdf.js:251:15)
      at Object.WorkerTransport (http://localhost:99/PDF/build/pdf.js:2305:9)
      at Object.getDocument (http://localhost:99/PDF/build/pdf.js:1805:15)
      at http://localhost:99/PDF/:6:10 pdf.js:251
  Warning: Unsupported feature "unknown" pdf.js:234
  Uncaught Error: No PDFJS.workerSrc specified
  </code></pre>
  
  <p>Do I need to manually specify <strong>pdf.worker.js</strong>?
  Please, what can I try to solve this?</p>
  
  <p>Thank you so much!</p>
  
  <p>(*) - I can see a lack of good content and a well explained documentation of PDF.JS.</p>