Widget showing "Empty timeline"-message


I’m trying to create an embedded widget with a hashtag search (#waterlandcup), but it shows the “Hmm, an empty timeline. That’s weird.”-message, even though there are a couple of tweets with this hashtag.

Check here for the widget: http://waterlandcup.nl/test/

But even if I do a search for this hashtag on the site, it doesn’t show all tweets. I tried to create another widget, with a hashtag search that does show several results (#futsaltalentcup), but that also shows the error-message: http://waterlandcup.nl/test-ftc-twitter/

I have searched the internet and this forum for a solution, but couldn’t find one that solves my problem. So I’m kind at a loss, what to do next. Hope somebody can help me