Sidebar disappeared

Hi guys,

A few days ago I did a bunch of plugin updates (I don’t like updates and always postpone them), and since I did that, the sidebar of my website has been removed. I am unable to find the source of this problem, which is why I am turning to you, the guys with more experience and know-how.

This is my website, and a page which should contain a sidebar:
http://www.fitnessbase.nl/kuiten/

I use the WP 4.2.2 and use the Pinboard theme.

I use a child-theme, but not in the first few days of the website. So it could be that an adjustment in a php page or whatever has gone lost, but I consider that a small possibility. Still I have no clue how to fix this and have been sitting with this problem for days now.

Your help will be greatly appreciated!