When you want to download some video from youtube with favorite tool youtube-dl, but this error shows up. That means the youtube-dl version that you’re using needs to be updated.
This is how to install the latest version of youtube-dl :
sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl sudo chmod a+rx /usr/local/bin/youtube-dl
Or if you installed with pip, you just upgrade it
sudo pip install --upgrade youtube_dl