<p dir="auto">With 3.0 I used "class="visible-xs visible-sm" to show a footer on small devices. After upgrading to 3.1 the footer wasn't shown.</p>
<p dir="auto">I changed it to "class="hidden-md hidden-lg" and then it was shown again.</p>
<p dir="auto">Not sure if this is/was an error in 3.0 or 3.1.</p>
<p dir="auto"><a href="https://dl.dropboxusercontent.com/u/37682778/error/index.html" rel="nofollow">https://dl.dropboxusercontent.com/u/37682778/error/index.html</a></p>