No video play, just sound

I've been trying to insert a video into my prezi with no succes. Ive tryed every supported format, and with all i get the same resut: no images playing, just the sound. Ive also tryed with different video lenghts, and i'm actually trying to insert a 1 sec one and i have the same issue. I'd really apreciatte some help. 

This is the link to my prezi

http://prezi.com/win9n_hothld/?utm_campaign=share&utm_medium=copy&rc=ex0share

Regards