Sorry to hear of the problem you are having.
You can resolve the issue by using new demo content installation method as described in the following topic.
Thank you for your response. Unfortunately, that didn’t quite solve the issue. When we upload the Construction Theme to our WordPress page, none of the demo imports — we would like the content from the demo in there (the pictures, the sliders, everything on the demo page) but none of that appears when we import it. The only thing from the theme that shows up is the bottom menu bar and the top contact menu.
Are you installing it as displayed in the attached screenshot?
If yes then would you mind if i log in to your site and do some troubleshooting? If this is ok then could you please share me your site log in details privately by adding them in the box having text “Click here to share private content. Only you and forum moderators will bee able see it.”?
If you want Construction demo content as it is on your site deleting your site content then you can achieve this first deleting your site content using the plugin https://wordpress.org/plugins/wordpress-reset/ then installing Construction demo content as described above.