As of March 4, 2014 the YouTube Data API (v2) was officially deprecated, and in early June 2015 was completely removed – meaning that any JW Player implementation which uses a YouTube playlist for it’s source (in the format shown below) will now fail to load:
Now, whilst there are new URL’s available allowing access to YouTube feeds without the need for an API key or oAUTH authentication, these don’t currently work in JW Player due to the feed/media structure not being compatible with JW Player’s expected Media RSS format:
Additionally they have restrictive CORS headers and appear to only return the latest 15 videos with no apparent way to page through the full feed…
Fortunately there is still a way you can make use of YouTube playlists in your JW Player setup.
Tubey is a JW Player plugin which, with a slight tweak to your configuration, will allow you to continue to load the full YouTube playlist. It also provides the ability to merge multiple YouTube playlists into one.