Ubuntu suddenly broke audio, apt-get and flash

Solution 1:

I know this is a bit old, but I got the same error with apt-get on Ubuntu GNOME 16.04.1 LTS. I found an old forum post that seemed to resolve the apt issues for me. Here are the steps it recommended:

sudo -i
apt-get clean
cd /var/lib/apt
mv lists lists.old
mkdir -p lists/partial
apt-get clean
apt-get update
cd
exit