Update: This issue was fixed in AdBlock for Edge 1.5.
Update November 10, 2016:
We've confirmed this is a bug in AdBlock for Edge version 1.4.
We're sorry this happened. We've removed the buggy code in AdBlock for Edge version 1.5, which is available in the Windows Store now. You should receive the update automatically. In the meantime, just reload the page and videos will play normally.
Our AdBlock for Edge 1.4 update, released this week, may have included a bug that's causing YouTube videos to play for about a millisecond before freezing on a black screen. Audio may or may not still play.
Our developer is investigating. We'll update this article as we learn more.
In the meantime, the workaround is to reload the page.
Thank you for your patience as we get this sorted!