Problems after update 4.6 and resolving the column issue

I had the same problem with post’s display in one column instead of three. After making the suggested changes here: (https://wordpress.org/support/topic/problems-after-update-to-46?replies=4) the problem with columns was resolved, but now the footer widgets disappeared. I checked, they should be there 🙂 So I wonder if the suggested code could cause that, or the problem lies in something else..