I am running Ubuntu 14.04. And added the ppa ppa:nathandyer/vocal-stable. After adding it, I runned sudo apt-get update and got the following error:
Fetched 13,1 kB in 8s (1478 B/s)
Reading package lists... DoneW: GPG error: http://deb.playonlinux.com
trusty InRelease: The following signatures couldn't be verified
because the public key is not available: NO_PUBKEY E0F72778C4676186W:
GPG error: http://extras.ubuntu.com trusty Release: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY 16126D3A3E5C1192W: GPG error:
http://archive.canonical.com trusty Release: The following signatures
couldn't be verified because the public key is not available:
NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32W: GPG error:
http://mega.nz ./ Release: The following signatures couldn't be
verified because the public key is not available: NO_PUBKEY
B258DF0B4D70F67AW: GPG error: http://nl.archive.ubuntu.com trusty
Release: The following signatures couldn't be verified because the
public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY
3B4FE6ACC0B21F32W: GPG error: http://nl.archive.ubuntu.com
trusty-updates Release: The following signatures couldn't be verified
because the public key is not available: NO_PUBKEY 40976EAF437D05B5
NO_PUBKEY 3B4FE6ACC0B21F32W: GPG error: http://nl.archive.ubuntu.com
trusty-backports Release: The following signatures couldn't be
verified because the public key is not available: NO_PUBKEY
40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32W: GPG error:
http://nl.archive.ubuntu.com trusty-security Release: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32W: GPG
error: http://repository.spotify.com stable InRelease: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY 082CCEDF94558F59W: GPG error:
https://private-ppa.launchpad.net quantal Release: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY E131728675254D99W: GPG error: https://repo.tox.im
nightly Release: The following signatures couldn't be verified because
the public key is not available: NO_PUBKEY 4B111B5D7DF12B85
I downloaded y-ppa manager and runned all the fixes, as seen in the screenshot below, but no luck.
I also purge the ppa:nathandyer/vocal-stable, and also locate everything connected with that ppa, and rm them.
Update from comment: My problem is already fixed. From someone outside of Ask Ubuntu. I asked him if I can post the steps to fixing this, here. Of course in quote format crediting him. Still waiting for reply!
