1. SSL Error: SELF_SIGNED_CERT_IN_CHAIN
When you try to install nodeJs packages like expressJS via package.json you may stuck up with this error. This is due to the fact that you are using an older version of npm and npm no longer supports its self-signed certificates.
To fix this
you can either upgrade your npm (it is what i did) using following command
npm install npm -g –ca=null
Or you can tell the npm to use existing registrars as below.
npm config set ca=””