Comment 2 for bug 1654087

I've found a workaround, which is basically to use the same process I used for 14.04. To wit:

echo "deb http://download.videolan.org/pub/debian/stable/ /" | sudo tee /etc/apt/sources.list.d/libdvdcss.list
echo "deb-src http://download.videolan.org/pub/debian/stable/ /" | sudo tee -a /etc/apt/sources.list.d/libdvdcss.list
sudo chmod a+r /etc/apt/sources.list.d/libdvdcss.list
wget -O - http://download.videolan.org/pub/debian/videolan-apt.asc|sudo apt-key add -
sudo apt-get update
sudo apt-get install libdvdcss2

Apparently xine and the current libdvdread doesn't like the current libdvdcss2; one needs to use the old one.