title: Universal Analytics event tracking
body: <p>I have JS code that runs on my clients' websites and occasionally reports certain events to GA so that the clients can track them (they are almost click events). For clients that use universal analytics the code I use is:</p>
  
  <pre><code>if (typeof ga != "undefined") ga('send', 'event', category, action,opt_label);
  </code></pre>
  
  <p>and usually it works correctly (I'm using the GA debugger extension for chrome to see which values are sent) however with a couple of clients the GA debugger extension returns an error:</p>
  
  <pre><code>Command ignored. Unknown target: undefined
  </code></pre>
  
  <p>What does the error mean and why does it happen only on some sites?</p>