Many Linux distros don’t have DVD support enabled by default. But by installing some video player like VLC etc, it gets automatically enabled so that you can play DVDs and watch videos on your laptop.
Open Terminal from your application launcher or use CTRL+ALT+T. Now type the given commands one by one and press ENTER.
sudo apt-get install libdvdread4
This not only works for Ubuntu, Elementary OS but also on Linux Mint and other Debian-based Linux distros.