Youtube fullscreen html5 export

Hi All,

I recently finished a eLearning project and exported it to HTML5. All is working correctly. The only problem is that the fullscreen function of my youtube movies (places with the Youtube widget) stopped working. On all browsers the fullscreen button of the player is not working. I tried to use the web page widget to embed a youtube clip but this also didn't work. Now I didn't even see the youtube clip. How can i solve it? Can it be fixed with simple script changes in the export files? Or should I do something else?

I'm using Captivate 7

Thanks in advance