At the beginning of 2015 Google published a "deprecation notice" for its YouTube ActionScript 3.0 Player API and all applications which relied on the functionality stopped working soon after the announcement.
WS.WebTV (with the EmbedClip extension) used the YouTube Flash Player API in order to playback YouTube videos directly using the native WS.WebTV Flash video player. Once the YouTube API fully stopped working all the EmbedClips which were using the YouTube direct playback stopped playing back (in Flash). It is worth noting that since long time ago, WS.WebTV supports the direct YouTube playback in HTML5.
Workarounds: For WS.WebTV 1.4.0.2 and previous
The only workaround is to manually edit all the EmbedClips which contain YouTube video URLs in the Flash slot of the video qualities and replace the YouTube video URL by the corresponding iframe Embed code.
For WS.WebTV 1.4.0.3 through 1.8:
Manually edit all the EmbedClips which contain YouTube video URLs in the Flash slot of the video qualities and add the [embed] prefix to the YouTube video URL, ONLY IN THE FLASH SLOT.
Additionally, you can use the workaround of the previous version.
For WS.WebTV 1.8.5+
Edit the config/Config.inc.php file and add the following before the PHP closing tag (?>):
$YOUTUBE_FLASH_DIRECT_PLAY = false;
Additionally, you can use the workarounds of the previous versions.
IMPORTANT NOTES:
- Verify each video after applying any workaround.
- After applying the workarounds the YouTube videos should playback again in Flash (as long as YouTube continues supporting Flash...) BUT you will lose the continuous playback functionality in Channels; therefore, if you have Channels with YouTube videos in their playlist, the playback will interrupt after each YouTube video and you will need to manually click "play" to resume playback and manually click "next" button to skip to the next video of the Channel's playlist.
- Please note that this will not affect the HTML5 video playback (at least at the moment) which uses the YouTube IFrame Player API.