Published story not advancing after video

I have published successfully but when I review and get to the point of a video demonstration, I can launch and view the demonstration (it opens in a separate window) but when i return to the elearning everything freezes. I cannot advance to the next slide or click on any menu items.

I have checked and the player trigger is set to advance to next slide when user clicks on next button.

There are about 4 video demonstrations but I can't get past the first one to see if the others do the same thing.

Help!