#24 worked for me BUT with the addition of removing leftover lock files first:
sudo rm /var/lib/dpkg/lock sudo rm /var/cache/apt/archives/lock
Dangerous if anything apt related still running - but I think a lot of people will CTRL-C their way out of "apt-get update" of somehow try to kill a hung update-manager.
#24 worked for me BUT with the addition of removing leftover lock files first:
sudo rm /var/lib/dpkg/lock apt/archives/ lock
sudo rm /var/cache/
Dangerous if anything apt related still running - but I think a lot of people will CTRL-C their way out of "apt-get update" of somehow try to kill a hung update-manager.