Docker hello-world: authentication error
Please run docker login at first time when you run any other docker commands.
You can log into any public or private repository for which you have credentials. When you log in, the command stores encoded credentials in
$HOME/.docker/config.jsonon Linux or%USERPROFILE%/.docker/config.jsonon Windows.
If you login through your emailId it does not works.
On windows login using your docker hub id.
You can access by your username.
Probably it can happen if you were logged in before, by console or by kitematic.
You can try docker logout if you want use docker without auth.
In this case Authentication is required: shouldn't appear again.