Error saying that public key is not available
Please look at the error message mentioned below.
It says “W: GPG error: http://ppa.launchpad.net natty release: The following signature couldn’t be verified because the public key is not available: NO_PUBKEY A6804EA8EAE0D85C”.
I visited the respective site, but found nothing. If you have any idea about the error message, please let me know.