Sorry, I don’t recall exactly what action solved it, but likely it is related to the content in each of widgets (and/or) in your footer. I would suggest you review the content of each of your widgets, ideally just deleting all content one by one (make sure you have a copy in a notepad file before, so you get put it back easily). Deleting each of the defined widgets may be even better than just erasing their content. It’s a good exercise anyway to make sure you can easily rebuild your site if you loose you widget content (after testing other templates or so).
At the time I also had a problem with the main menu not having been defined yet. Not sure it was related though. I was using the default display of the main menu, but that wasn’t enough for the mobile size menu to display (in a drop down box when the screen width is really narrow) so I manually created a main menu and assigned it. That also allowed me to sort the items and only include those that I needed.