I get the following error when i do
sudo apt-get update
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6AF0E940624A220
I tried following ways after reading various questions here and also by googling.
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6AF0E1940624A220
It did not help. I also tried
sudo gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys
thinking port 11371(default) may be blocked due to firewall.
I also tried to reset everything as follows
sudo rm /var/lib/apt/lists/* -vf sudo apt-get update && sudo apt-get upgrade
still i get the same error or get update. Any other possible solution I can try?