<p dir="auto">Challenge <a href="http://www.freecodecamp.com/challenges/say-hello-to-html-elements" rel="nofollow">Say Hello to HTML Elements</a> has an issue.<br>
User Agent is: <code class="notranslate">Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36</code>.<br>
Please describe how to reproduce this issue, and include links to screenshots if possible.</p>
<p dir="auto">My code:</p>
<div class="highlight highlight-text-html-basic notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&lt;h1&gt;Hello World&lt;/h1&gt;
"><pre class="notranslate"><span class="pl-kos">&lt;</span><span class="pl-ent">h1</span><span class="pl-kos">&gt;</span>Hello World<span class="pl-kos">&lt;/</span><span class="pl-ent">h1</span><span class="pl-kos">&gt;</span></pre></div>
<p dir="auto">Uncaught TypeError: Cannot read property 'join' of null</p>
<p dir="auto">vendor-main-00eff8238f.js:30</p>
<p dir="auto">I cann't press the button "Submit and go to my next challenge (ctrl + enter)". But if I clicked I only see the infinite loading. How to solve this problem?<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/15948159/12712716/62a3c88c-c8db-11e5-9556-7183e96aa60b.PNG"><img src="https://cloud.githubusercontent.com/assets/15948159/12712716/62a3c88c-c8db-11e5-9556-7183e96aa60b.PNG" alt="default" style="max-width: 100%;"></a></p>