Using a terminal you may wish to give a chance to youtube-dl which can be easily installed by dropping sudo apt-get install youtube-dl and its usage is quite easy: simply copy the youtube url and add it in the terminal just after youtube-dl as shown in the next example:
youtube-dl http://www.youtube.com/watch?v=yQEaXAoB6Ck
This code will download Baltimora Chinese Restaurant video.
This will resut in the flv video to be downloaded in the folder where the terminal resides at the very moment that you start downloading, so make sure you first change directory to your videos folder.
Another excellent option is via GUI, by using Mobile Media Converter by MikSoft
And or JDownloader. JDownloader will also allow you to choose which video format you want to donload based on the available formats in youtube, which may include but not limited to: mp4, flv, ogv, mp3 and a few other.
Good luck!
The first video downloaded successfully with a recently updated version of youtube-dl which I installed with python-pip using python pip install youtube-dl inside a Python virtual environment (python-virtualenv). For information about how to setup and use a Python virtual environment see How to set up and use a virtual python environment in Ubuntu?.
The command I used to show the available video formats was:
youtube-dl -F "https://www.youtube.com/watch?v=wo6Sq1h2DI4"
The command I used to download the first YouTube video was:
youtube-dl -f 18 "https://www.youtube.com/watch?v=wo6Sq1h2DI4"
The second video could not be downloaded using youtube-dl, but I did not give up. I upgraded my youtube-dl to the latest version by running:
pip install --upgrade youtube-dl # inside the Python virtual environment
I didn't need to use sudo because my Python virtual environment was installed inside my own user directory (~/my-Python-virtual-env). After upgrading youtube-dl I ran this command to download the second YouTube video:
youtube-dl -f 18 "https://www.youtube.com/watch?v=BbbhZl8xqVY"
Why not simply use sudo pip install --upgrade youtube-dl ?
One of the reasons I use Ubuntu is to escape the madness of the way Windows installs applications. I install packages from the default Ubuntu repositories whenever possible. In this case I know that youtube-dl is a Python program, so I can locally install the latest version of youtube-dl in a Python virtual environment without messing up my filesystem.
Another alternative is to install the youtube-dl snap package:
sudo snap install youtube-dl # start with snap run youtube-dl
I believe that since from now some things have changed in YouTube's service and applications' way to access it.
True. Google has been changing the way to access YouTube videos more frequently now than was the case three years ago, so in order to keep youtube-dl up-to-date, it has to be updated more frequently too. I have observed over the years that YouTube videos appear to be blocked mostly related to the date when they were uploaded.
Before I started using youtube-dl, I used a Firefox extension called Video DownloadHelper to download YouTube videos. I have come to prefer youtube-dl because it has the highest probability of successfully grabbing YouTube videos of any downloader that I have ever used.
Best Answer
The policy issue is with YouTube, rather than with Ubuntu or the YouTube downloader. To answer the technical part of the question:
Ensure you are running the latest version.
Not ideal but it works.