Never used media, but "No video with support format and MIME type found." is a HTML5 video tag error. Inspect the gray box in your browser's debug console and see if it's actually listing <source> tags inside of the <video> tag. If it is, then check that they have the type attribute and it is pointing to a supported mime type that your browser supports (recent browsers support video/mp4. Chrome and FF also support video/webm). 
Jamie Holly
http://hollyit.net
On 1/21/2014 4:55 PM, Nancy Wichmann wrote:
Yes, and the File Entity module too. I'm just getting a gray box instead of a play window. The box says "No video with support format and MIME type found."

The issue queues have not been terribly helpful. It seems that there is a lot of module bouncing going on with the three of them.

I may have to drop back to 7.x-1.x.
 
Nancy

From: Steve Kessler <skessler@denverdataman.com>

Have you installed the Media You Tube module  (https://drupal.org/project/media_youtube).  It just works to add itsself t the web tab on the media insert button. It has just worked for me but I would be glad to answer any specific questions.

Hope this helps.  

-Steve