First, you need to change it back to <button class="menu-toggle"> or the JavaScript that toggles the menu won’t work. That hack was for an older version and the issue described in that thread has been fixed.
Once you’ve done that, if the menu still doesn’t open, please come back and post a link to your site.
Okay, I’ve changed it back, and I’m back where I started.
The website is http://annasheehan.com/
The JavaScript that toggles the menu isn’t loading at all on your site. Has footer.php been modified in any way?
Ah, yes. It has, actually.
I took out the footer coding so that it wouldn’t say ‘made using WordPress’ or whatever.
What should I be putting back in?
Nevermind. I got it.
Thanks!