I have never been able to use this Auto Embed feature. I started out with version 3.5.1, and upgrading has not helped. If I used [embed] code, it works. I have tried deactivating video plugins I have and some others, but it was the same. It was not working even before I installed all kinds of plugins anyway . . .
When I copy the Web address for the video, only the URL text shows up on the Web page.
I am doing OK with a plugIn to supplement, but it would be nice to have the function. Does anybody have any idea what might be the issue?