youtube-dl is not working

view story

http://askubuntu.com – I am using youtube-dl to download some videos from youtube. But when I write: youtube-dl http://www.youtube.com/watch?v=rn_YodiJO6k I get: [youtube] Setting language [youtube] rn_YodiJO6k: Downloading video webpage [youtube] rn_YodiJO6k: Downloading video info webpage [youtube] rn_YodiJO6k: Extracting video information ERROR: unable to download video What am I doing wrong? (HowTos)