Facebook can't scrape our website

Hi there!

I’m running https://www.workoutsquad.nl now for two years. Last week we updated WordPress from 3.5.something to 3.9.2. No errors occured, everything went fine. We’re using theme Gonzo from themeforest and also updated the theme, also without any problems.

Since this update we can’t post blogposts to Facebook with a preview anymore. We tried to use the Facebook Debug Tool and we receive this message “Error parsing input URL, no data was cached, or no data was scraped.”. If we click the “See exactly what our scraper sees for your URL” link we see this message “Document returned no data”.

This problem doesn’t occur on, for example, Google+. Website is working fine, DNS settings seems to be right and no minify plugins are used.

We’re not running much plugins. Only disqus, woocommerce and yoast. Before this we used All in one SEO and tried to switch to yoast hoping this was fixing the problem but without any luck. Also with yoast disabled the same problem.

After hours searching and Googling still no solution. Anyone have an idea what’s wrong with our WordPress website?

Thanks in advance!
Kelly