first of all thanks for the really nice theme :)
I'm using the Timely calendar (1.10.11-standard) to display upcoming events in the sidebar. The problem is hard to describe but easy to see in the screenshot:
As you can see the widget is using the end of the text in the main content area as value for the vertical size of the widget and therefore pushing the other widgets down.
If I use the theme "twenty fourteen" it does not happen, so I assume some error in your theme.
(I also tested for plugin conflicts)
How can I debug/fix this?