Font loading error: downloadable font: kern: Too large subtable, table discarded
<p>I am trying to use the "Open sans" font into my web page, and <em>only</em> in Firefox, I get this error in console:</p>

<blockquote>
  <p>downloadable font: kern: Too large subtable, table discarded</p>
</blockquote>

<p>Here is the CSS:</p>

<pre><code>@font-face {
    font-family: Open Sans;
    src: url(OpenSans-Semibold.ttf);
}
</code></pre>