We pushed a fix for internal server errors, but I also see a few changes to be made with your tags. The above tags are different from the ones currently in the example URL, so I’ll look at each set individually.
Concerning the tags above, the twitter:player value is invalid because the player URL must be a secure connection (in other words, a URL that starts with https://). Once it’s servered over SSL, the player should display.
The tags I’m currently seeing on the example URL will not display because your player URL is a YouTube page, and if you wanted to show this video it would need to be its embedded URL. Also, the correct dimension tags for the YouTube video would have been 1280x720, but I assume you were just trying things out with their player in place of yours.
And the twitter:player:stream tags would not be necessary since YouTube does not have a streaming file you can connect to directly. They leave this out intentionally to expire mp4 links. Hopefully this helps!
