I recently stopped being able to get updates for Ubuntu 12.04. Using Update manager, I now have 105 updates (almost 300mb) waiting, but everytime I click "Install", a window comes up with this message:
CD/DVD 'Ubuntu 14.04.1 LTS _Trusty Tahr_ - Release i386 (20140722.2)' is required
I don't know why I need to do this, but I downloaded an .iso version of that, put it in my DVD/CD drive, and still get the same warning window. I've tried updating from a terminal (sudo apt-get update) and, after a long list of archives I get this warning at the end (and no updating):
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ precise/partner i386 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems
Anybody know what's going on? This has just been happening over the last few weeks.
cat /etc/apt/sources.list; tail +1 /etc/apt/sources.list.d/*.list
in your question, by editing it.