I experienced some problems when loading the MOOC videos as shown in the screenshot below
My solution was following the steps shown here, that is, first verify that the multiverse repository is enabled on your system:
sudo add-apt-repository multiverse
And then you can install it in Ubuntu default edition using this command:
sudo apt install ubuntu-restricted-extras
After accepting the EULA license terms it is just a matter of restarting the computer. Hope this helps someone!