Followed instructions on How to play a DVD on Loki, but the DVD video would just not play decoded. Sound is ok. But DVD menus and video content remain encrypted. Running loki 0.4.1 on a 2006 2,1 MacBook Pro 17", using VLC to read DVDs. De-installed Videos. De-installing libdvd-pkg, reinstalling, including VLC then rebooting doesn't solve the problem.
This answer will likely not help, but it is worth a shot.
To make movies and music work on Ubuntu run these commands.
sudo apt-get install ubuntu-restricted-extras libdvd-pkg
sudo dpkg-reconfigure libdvd-pkg
After that, since VLC is not working, try totem.
sudo apt-get install totem
reboot the computer, just for good measure, then try to open and play your DVD.