I had the same issue. I thought I broke my configuration. I googled for "thirty bees left column not shown" ;-)
I went in Prefs > Themes > Advanced. Then for the specific page you are showing, it's name is "category". Make sure you tick the left column.
You can do this for every page you want. Let say you want to have a right column on index page, you tick "right column" in this page. Change is immediate (on my instance though).
Hope this will help you and other.