RSpec::Core::Configuration::MustBeConfiguredBeforeExampleGroupsError

Came across this weird error: 

This had happened because I had RSpec 1 way of including spec_helper (in old files):

require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')

And the other way (in my new files):

require 'spec_helper'

Synching them fixed it :))