There is nothing wrong with the Theme.
I am able to disable footer widget area or footer copyright.
Please see my screen-cast.
There is something wrong on your website, which I do not know why.
That is why I provided a plugin to try and fix it for you.
Since my plugin does not work for you, please remove it.
Perhaps you should disable your plugins to find out which plugin is causing this issue.
You can also check if your theme is updated to latest version.