I'm new to Ubuntu and having some trouble after installing Atom. First time I failed and removed it. Second time I succeeded and got it running.
But now when I run sudo apt-get update
I get the following error:
W: GPG error: https://packagecloud.io/AtomEditor/atom/any any InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4C6E74D6C0A35108
W: The repository 'https://packagecloud.io/AtomEditor/atom/any any InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
How can I fix this problem?