I have the solution for this problem. TRY THIS. copy the embed code for your video copy it on a new WEB PAGE of MICROSOFT FRONTPAGE. Next preview it and click on your video (on the web page) and watch it. Next refresh your page and this "image coming soon" had been replaced. (dont comment my english becouse i'm portuguese. lol)
hope it works with you guys.
To dla mnie bardzo waż
ne. Będę niezmiernie wdzięczna za pomoc.