Saya mengalami masalah dengan yang berikut ini (dalam upaya untuk menghapus hyperlink, saya telah menghapus salah satu "/" dari alamat-alamat):
W: GPG error: http://archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG B725097B3ACC3965 Launchpad lffl
W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG 4874D3686E80C6B7 Launchpad PPA for Banshee Team
W: GPG error: http://archive.getdeb.net jaunty-getdeb Release: The following signatures were invalid: BADSIG A8A515F046D7E7CF GetDeb Archive Automatic Signing Key <archive@getdeb.net>
W: GPG error: http://badgerports.org lucid Release: The following signatures were invalid: BADSIG C90F9CB90E1FAD0C Jo Shields <directhex@apebox.org>
W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG 976B5901365C5CA1 Launchpad PPA for transmissionbt
W: Failed to fetch http://ppa.launchpad.net/dlecan/openjdk/ubuntu/dists/oneiric/main/source/Sources 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/dlecan/openjdk/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/sevenmachines/flash/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/sun-java-community-team/sun-java6/ubuntu/dists/oneiric/main/source/Sources 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/sun-java-community-team/sun-java6/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found
Saya telah mencoba solusi berikut yang dalam kasus tertutup berjudul "Tanda tangan berikut tidak valid":
First of all try
sudo apt-get clean
sudo apt-get update && sudo apt-get upgrade
Some ISPs cache the packages and errors like these are reported then.
If the above commands don't work, try
sudo apt-get update -o Acquire::http::No-Cache=True
and again
sudo apt-get update && sudo apt-get upgrade
If it still doesn't work,
sudo apt-get update -o Acquire::BrokenProxy=true
sudo apt-get update && sudo apt-get upgrade