This problem is not only faced by me. This is the output from my friends laptop:
sudo apt-get update Ign http://archive.canonical.com natty InRelease Ign http://in.archive.ubuntu.com natty InRelease Ign http://ppa.launchpad.net natty InRelease Ign http://archive.ubuntu.com natty InRelease Ign http://extras.ubuntu.com natty InRelease Hit http://archive.canonical.com natty Release.gpg Ign http://in.archive.ubuntu.com natty-updates InRelease Ign http://ppa.launchpad.net natty InRelease Hit http://archive.ubuntu.com natty Release.gpg Hit http://archive.canonical.com natty Release Ign http://in.archive.ubuntu.com natty-security InRelease Ign http://ppa.launchpad.net natty InRelease Hit http://archive.ubuntu.com natty Release Ign http://in.archive.ubuntu.com natty-proposed InRelease Hit http://extras.ubuntu.com natty Release.gpg Get:1 http://ppa.launchpad.net natty Release.gpg [316 B] Hit http://archive.canonical.com natty/partner Sources Hit http://archive.ubuntu.com natty/main Sources Hit http://in.archive.ubuntu.com natty Release.gpg Get:2 http://ppa.launchpad.net natty Release.gpg [316 B] Hit http://archive.canonical.com natty/partner amd64 Packages Hit http://archive.ubuntu.com natty/restricted Sources Hit http://in.archive.ubuntu.com natty-updates Release.gpg Hit http://ppa.launchpad.net natty Release.gpg Ign http://archive.canonical.com natty/partner TranslationIndex Hit http://extras.ubuntu.com natty Release Hit http://in.archive.ubuntu.com natty-security Release.gpg Get:3 http://ppa.launchpad.net natty Release [9,757 B] Ign http://ppa.launchpad.net natty Release Hit http://in.archive.ubuntu.com natty-proposed Release.gpg Get:4 http://ppa.launchpad.net natty Release [9,736 B] Ign http://ppa.launchpad.net natty Release Hit http://in.archive.ubuntu.com natty Release Hit http://ppa.launchpad.net natty Release Hit http://extras.ubuntu.com natty/main Sources Hit http://in.archive.ubuntu.com natty-updates Release Ign http://ppa.launchpad.net natty/main Sources/DiffIndex Hit http://in.archive.ubuntu.com natty-security Release Ign http://ppa.launchpad.net natty/main amd64 Packages/DiffIndex Hit http://in.archive.ubuntu.com natty-proposed Release Ign http://ppa.launchpad.net natty/main TranslationIndex Hit http://extras.ubuntu.com natty/main amd64 Packages Hit http://in.archive.ubuntu.com natty/restricted Sources Hit http://ppa.launchpad.net natty/main Sources/DiffIndex W: GPG error: http://ppa.launchpad.net natty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C0B56813051D8B58 W: GPG error: http://ppa.launchpad.net natty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A6804EA8EAE0D85C E: Could not open file /var/lib/apt/lists/ppa.launchpad.net_n-muench_burg_ubuntu_dists_natty_main_source_Sources.IndexDiff - open (2: No such file or directory) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/803040 Title: Cannot update or install packages To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/803040/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
