title: d3.json doesn't call callback function
body: <p>I'm trying to get started with d3.js and something isn't right. I have this tag in my <code>&lt;head&gt;</code> section</p>
  <pre><code>&lt;script src=&quot;https://d3js.org/d3.v5.min.js&quot;&gt;&lt;/script&gt;
  </code></pre>
  <p>and this code in my javascript file</p>
  <pre><code>d3.json('http://localhost:53526/api/foo', function (data) {
      console.log(data);
  });
  </code></pre>
  <p>The problem is the call back never happens. No data is ever logged. Here's my javascript console: <a href="https://i.stack.imgur.com/SVdxC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SVdxC.png" alt="enter image description here" /></a></p>
  <p>But I can see the data from my json api in the network tab! <a href="https://i.stack.imgur.com/8WcxL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8WcxL.png" alt="enter image description here" /></a> It has sent a request and the request was successful but yet it doesn't call the callback function.</p>
  <p>I've also read many examples of people using <code>d3.request(url).get</code> but whenever I try this I just get the error message</p>
  <blockquote>
  <p>Uncaught TypeError: d3.request is not a function</p>
  </blockquote>
  <p>I'm getting the exact same behavior from both Chrome and Firefox. Have I missed something very basic here? Why doesn't d3 load any data?</p>