Images disappeared with Page Builder

I have a WordPress 4.5.3 site using the Create theme by ThemeTrust. It is built using the SiteOrigin PageBuilder plugin, and it was working just fine until today. For what seems to be no apparent reason, suddenly most of the images on the site have disappeared. When I went through the WordPress forums, they recommended deactivating the theme and all plugins and then reactivating them one at a time in order to determine which might be causing the problem. When I did so, it appears that PageBuilder is the issue. The images show up when the plugin is deactivated (though the layout is messed up), but they disappear when it is activated (and the layout is restored). Any ideas about what might be causing the issue, or how to fix it?