Iam a severe beginner, so please bear with me ...
I un-installed playonlinux from my machine*. Now, whenever running sudo apt-get update, the system still prints these warnings:
W: GPG error: http://deb.playonlinux.com precise InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A
W: The repository 'http://deb.playonlinux.com precise InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
When I look at sources.list, it does not contain any reference to playonlinux that I can identify. I also ran apt-key update. When I try to purge playonlinux, it says that Package 'playonlinux' is not installed.
How can I fix this? Thanks!
*I am running Elementary OS 0.4.1. (Built on "Ubuntu 16.04.2 LTS").
