YouTube changed their "share" URLs recently and an official definition update hasn't been released yet. I believe a couple of options were posted earlier (recently) in this thread- either try an
unofficial definition or copy a youtube url from the browser address bar, note a share url.
Looking at your link the first video you posted shows the YouTube video icon next to it, so it did attempt to embed but for some reason it believes that video is not allowed to be embedded. What code do you have in your AME Definition in your
Validation box? Consider removing it and trying again.