I am running Netrunner Dryland Second Edition and since a few days Muon displays the following errors when updating:
Failed to download http://ppa.launchpad.net/cyberspace/ppa/ubuntu/dists/precise/main/source/Sources
404 Not Found
Failed to download http://ppa.launchpad.net/cyberspace/ppa/ubuntu/dists/precise/main/binary-amd64/Packages
404 Not Found
Failed to download http://ppa.launchpad.net/cyberspace/ppa/ubuntu/dists/precise/main/binary-i386/Packages
404 Not Found
Please dont let me down just because I am running an older version - it is an LTS, being based on 12.04, and I have been sticking with netrunner for a long time now and have newer versions installed on other machines, but cant upgrade this one.