Ruby on Rails - Autoprefixer doesn’t support Node v4.9.1. Update it. How to fix?

For future searchers, we on our team can only duplicate this error on Ubuntu environment.(Tried it on iOS and Ubuntu 16.04 only)

Already tried installing the latest Node.js versions, to no avail.

There is a link in my question that talks about how this is happening and how to fix it.

So the solution was by installing the mini_racer gem to your rails app.