GPG error: http://ppa.launchpad.net/ondrej/php/ubuntu xenial InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 4F4EA0AAE5267A6C

The following signatures couldn't be verified

To fix Ubuntu 16.04 error: GPG error: http://ppa.launchpad.net/ondrej/php/ubuntu xenial InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 4F4EA0AAE5267A6C run: # apt-key adv –keyserver keyserver.ubuntu.com –recv-keys 4F4EA0AAE5267A6C Sample output:     If you like… Continue Reading