WordPress 4.7.1 recently rolled out and one of the things that is no longer working is the Widget Importer/Exporter plugin. This plugin is what we use to import the demo widget settings that the theme demo is using. The Plugin Authors have addressed this issue here and recommended a fix until WordPress 4.7.2 rolls out.
Download and install this plugin Disable Real MIME Check. Once you install and activate that plugin you can follow through with the Widget Import just like you normally would. Once the widget import is finished, delete the “Widget Import/Export” plugin and also the “Disable Real MIME Check” plugin. If you have any issues please contact us. We would love to help.