I did a fresh install of UbuntuGNOME 13.10. During the installation, I had checked both the options for downloading updates and installing third-party softwares. But it seems that third-party softwares are not installed. I cannot play media files such as mp3, mp4 etc. Also, flash content cannot be played on websites. I'll install VLC to play media files. But, why was third-party softwares not installed? I have a working Internet connection.
Run the below command on terminal(ctrl+alt+t) to install Ubuntu Restricted extras,
sudo apt-get update sudo apt-get install ubuntu-restricted-extras