I just added a video to one of my site pages by editing page -> insert -> Video and Audio -> From Computer. The video is on the page now and works, but every time I load the page this message pops up.
I click OK and everything is fine. Not sure if this could have screwed anything up, but when I added this video, there was another one on the page. I didn't even need to delete the old one. This new one loaded in just fine, but it automatically deleted the older one from the page.