Sidebar disappeared and widgets not working

I recently updated WordPress and my colinear theme, and when I did that my sidebar disappeared. My widgets still show up, but they are at the bottom of the page underneath the main content instead of in a sidebar. When I go to widgets in my dashboard, they show as being in the sidebar, but they don’t display there. I’ve tried deactivating all the plugins, to no avail. I also tried live previews of different themes, including 2016 and 2015, but that didn’t work either. With all themes, when I’m in the customizer and click on widgets I get this message: “There are no widget areas currently rendered in the preview. Navigate in the preview to a template that makes use of a widget area in order to access its widgets here.”

Help?!