title: Problems reading JSON file in D3 javascript in some (not all) browsers
body: <p>I get this error in Chrome immediately after reading a JSON file. It works correctly in Safari and Firefox.</p>
  
  <blockquote>
    <p>console.log ("event -> "+ postcards.nodes[0].node.event); // "tally" in Safari "TypeError: Cannot read property 'node' of undefined" in Chrome.&lt;</p>
  </blockquote>
  
  <p>Is there a limit to the levels in a nested JSON file? I generate the JSON from a Drupal view. Here here is the start: </p>
  
  <pre><code>{"nodes":[{"node":{"w1":"","w2":"1","w3":"","w4":"", ...&lt;
  </code></pre>
  
  <p>Here is the Javascript:</p>
  
  <pre><code>d3.json(
    "/sites/default/d3_files/json/toronto-wards.json", 
    function(error,wards) {
      d3.json("/postcards-json", function(error, postcards) {
        console.log ("event -&gt; "+ postcards.nodes[0].node.event); // tally in Safari
  </code></pre>
  
  <p>I'm using macOS and my friends using Windows get the same error in Firefox.</p>
  
  <p>As per request here is what I think is the XHR message:</p>
  
  <pre><code>d3.min.js:1 XHR finished loading: GET "http://www.stopplastics.ca/postcards-json".
  </code></pre>