Ubuntu 12.04 apt-get update GPG error -

Ubuntu 12.04 apt-get update GPG error -

my goal upgrading ubuntu 12.04 lts 14.04 lts. don't have running surface, because it's used issue tracking server. @ first wanted update current system.

after sudo apt-get update this:

ok http://archive.canonical.com precise release.gpg ok http://archive.canonical.com precise release hole:1 http://archive.ubuntu.com precise release.gpg [198 b] ok http://archive.canonical.com precise/partner sources ok http://archive.canonical.com precise/partner amd64 packages hole:2 http://archive.ubuntu.com precise-updates release.gpg [198 b] ok http://archive.canonical.com precise/partner i386 packages ign http://archive.canonical.com precise/partner translationindex hole:3 http://archive.ubuntu.com precise-security release.gpg [198 b] ok http://archive.ubuntu.com precise release ign http://archive.ubuntu.com precise release hole:4 http://archive.ubuntu.com precise-updates release [49,6 kb] ign http://archive.ubuntu.com precise-updates release hole:5 http://archive.ubuntu.com precise-security release [49,6 kb] ign http://archive.ubuntu.com precise-security release w: gpg-fehler: http://archive.ubuntu.com precise release: die folgenden signaturen waren ungültig: badsig 40976eaf437d05b5 ubuntu archive automatic signing key <ftpmaster@ubuntu.com> w: gpg-fehler: http://archive.ubuntu.com precise-updates release: die folgenden signaturen waren ungültig: badsig 40976eaf437d05b5 ubuntu archive automatic signing key <ftpmaster@ubuntu.com> e: gpg-fehler: http://archive.ubuntu.com precise-security release: die folgenden signaturen waren ungültig: nodata 2

after tried

sudo rm /var/lib/apt/lists/* -vf sudo apt-get update && sudo apt-get upgrade

because thought error results in wrong entry in sources.list, course of study didn't change.

then tried key with

gpg --keyserver keyserver.ubuntu.com --recv 40976eaf437d05b5

which resulted in

gpg: requesting key 437d05b5 hkp server keyserver.ubuntu.com gpgkeys: key 40976eaf437d05b5 not found on keyserver gpg: no valid openpgp info found. gpg: total number processed: 0

at point don't know anymore, hoping help!

greetings, vach

solved problem by:

visit keyserver.ubuntu.com

search missing key:

0x40976eaf437d05b5

(note 0x before key)

click on link on pub section , re-create whole content origin

-----begin

and save content new file "key"

add key manually: sudo apt-key add together key (followed ok response)

updating 1 time again sudo apt-get update works fine

ubuntu