Video doesn´t run on the web site

Hi
We moved our wordpress website from an other theme to the theme highend.
Now the video (currently only one uploaded) on our website doesn´t run. Instead of the running video I have black box. See attachement.

If I open the editor to edit the post, the video is running within the editor.

The code for the embedded vidoe looks like:
[video width="460" height="240" mp4="http://www.wipr.info/wp-content/uploads/2015/09/TEST_Film_x264_small2.mp4" poster="http://www.wipr.info/wp-content/uploads/2015/09/image11-e1442260104558.jpg" preload="none" autoplay="off"][/video]

I didn´t find any hint on this forum.
Thanks in advance for your support.
regards,
Philippe