Yes it's broken, but then it's not. You can literally change 'videoseries' to anything else and it will work. in fact, you can have it like this and still works: https://www.youtube.com/embed/?list=YOUR-PLAYLIST-ID
Yes it's broken, but then it's not. You can literally change 'videoseries' to anything else and it will work. in fact, you can have it like this and still works: https://www.youtube.com/embed/?list=YOUR-PLAYLIST-ID