title: CasperJS screenshot gives a blank screen
body: <p>I've been banging my head with this one.</p>
  
  <p>I'm running on casperjs 1.1.0-beta3 using phantomjs 1.9.8</p>
  
  <p>I'm trying to capture an image from url and save it a file.</p>
  
  <p>This is my command:</p>
  
  <pre><code>casperjs --proxy-type=none --ssl-protocol=any /home/casper-capture.js http://url.com/demo/demo /home/demoScreenshot.png
  </code></pre>
  
  <p>This is my <strong>casper-capture.js</strong></p>
  
  <pre><code>/**
  * capture image from url and save it to file.
  **/
  var casper = require('casper').create({
      verbose: true,
      logLevel: "debug",
       viewportSize: {
          width: 2300,
          height: 1200
      },
      pageSettings: {
          webSecurityEnabled: false,
          loadImages:  true,        // The WebPage instance used by Casper will
          loadPlugins: true         // use these settings
      }
  });
  // delay before image capturing
  var delay = 60000;
  //timeout delay for loading
  var timeoutForLoading = 10 * 60000;
  // image source url.
  var url = casper.cli.args[0];
  // image output path
  var path = casper.cli.args[1];
  
  casper.start().zoom(4).thenOpen(url, function urlCaptureClouser() {
      this.wait(delay, function(){
          casper.waitFor(function check() {
              return this.evaluate(function() {
                  return document.querySelectorAll('.fa-spin').length +
                          document.querySelectorAll('.chart-loading').length == 0;
              });
          }, function then() {
             this.capture(path);
          }, function then() {
              this.capture(path);
          }, timeoutForLoading);
      });
  });
  
  casper.run();
  </code></pre>
  
  <p>I'm getting a "blank" screen. :-(</p>
  
  <p>When I run it on my local system. It works! I'm not sure what I am doing wrong.</p>
  
  <p>Can someone please pin point my issue?</p>
  
  <p>Console log (with error logging):</p>
  
  <pre class="lang-none prettyprint-override"><code>[info] [phantom] Starting...
  [info] [phantom] Running suite: 2 steps
  [debug] [phantom] opening url: &lt;URL&gt;, HTTP GET
  [debug] [phantom] Navigation requested: url=&lt;URL&gt;, type=Other, willNavigate=true, isMainFrame=true
  [debug] [phantom] url changed to "&lt;URL&gt;"
  Error: TypeError: 'undefined' is not an object (evaluating 'Object.assign.apply')
  [debug] [phantom] Successfully injected Casper client-side utilities
  [info] [phantom] Step urlCaptureClouser 2/2 &lt;URL&gt; (HTTP 200)
  [info] [phantom] Step urlCaptureClouser 2/2: done in 329ms.
  [info] [phantom] Step _step 3/3 &lt;URL&gt; (HTTP 200)
  [info] [phantom] Step _step 3/3: done in 351ms.
  [info] [phantom] wait() finished waiting for 60000ms.
  [info] [phantom] Step _step 4/4 &lt;URL&gt; (HTTP 200)
  [info] [phantom] Step _step 4/4: done in 60358ms.
  [info] [phantom] waitFor() finished in 41ms.
  [info] [phantom] Step then 5/5 &lt;URL&gt; (HTTP 200)
  [debug] [phantom] Capturing page to /home/dmeo1991.png
  [info] [phantom] Capture saved to /home/dmeo1991.png
  [info] [phantom] Step then 5/5: done in 60674ms.
  [info] [phantom] Done 5 steps in 60674ms
  Unsafe JavaScript attempt to access frame with URL about:blank from frame with URL file:///usr/lib/node_modules/casperjs/bin/bootstrap.js. Domains, protocols and ports must match.
  </code></pre>