Fehler
....
Ign http://de.archive.ubuntu.com trusty-backports/universe Translation-en_US
Fetched 30.2 MB in 13s (2,207 kB/s)
Reading package lists... Done
W: GPG error: http://de.archive.ubuntu.com trusty-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
Lösung
root:~# apt-get clean
root:~# cd /var/lib/apt
root:~# mv lists lists.old
root:~# mkdir -p lists/partial
root:~# apt-get clean
root:~# apt-get update