You may have a Web site that uses copious amounts of YouTube videos that solely rely on Flash player across your many pages. Chances are you have embedded which makes use of the ActionScript player. Further chances are that you are using an ActionScript 3-based player. There is a small chance, however, that you're still using ActionScript 2. If that's the case, YouTube has news for you.
The video streaming site has alerted the masses via their blog that they're changing the default selection when using a URL like this - http://www.youtube.com/v/VIDEO_ID. When this happened, it would select an ActionScript 2-based player by default unless you specifically added in a version=3 into the code. Starting May 2, it will now default to ActionScript 3.
The team points out that this change affects both embedded and Chromeless Flash players. You have nothing to worry about if you're using the newest iframe embedded player. This means that the vast majority of developers and users are already using ActionScript 3 when using Flash playback.
Now, what about the tiny majority making their voice heard among the masses demanding their ActionScript 2 versions? Easy enough, just add the version=2 URL parameter into your player URL. This will fix it right up and won't cause any compatibility problems.
Of course, this is only a temporary solution to your problem of being behind in the times. In an effort to make you ActionScript 2 users feel old, YouTube points out that ActionScript 2 has been deprecated for several years now. Enough is enough, time to let the relentless march of time take its toll. To that end, YouTube is shutting down its ActionScript 2 support in October. You have until then to move everything over to ActionScript 3.
Once again, the majority of users don't have to worry about a thing. This is only for those who still rely on old versions of ActionScript to keep their videos up and running. While there is something to be said on being retro, I don't think it applies to YouTube videos.