W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.<br>GPG error: http://archive.canonical.com precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email@example.com>
I issued the following command:
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5
And got the following message:
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /tmp/tmp.VE2O5iyxt2 --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5 gpg: requesting key 437D05B5 from hkp server keyserver.ubuntu.com gpg: key 437D05B5: "Ubuntu Archive Automatic Signing Key <firstname.lastname@example.org>" 25 new signatures gpg: no ultimately trusted keys found gpg: Total number processed: 1 gpg: new signatures: 25
Tried the series of commands from this posting:
Tried using Y-PPA-Manager:
Nothing has worked so far.