language file errors during upgrade from 2.1.4 to 3.0.0

Just to preface, I have read and followed the step-by-step upgrade instructions found at http://www.codeigniter.com/user_guide/in...e_300.html.  I've also searched but I was unable to come up with a solution that has fixed my problem.

My production CI 2.1.4 web application works with no errors.  However when I clone that to my dev version and walk through the upgrade instructions I get the following error: "Unable to load the requested language file: language/en/en_lang.php"

en_lang.php does not exist and has never existed.

autoload.php

Code:

$autoload['language'] = array('common', 'config', 'customers', 'employees', 'error', 'items', 'login', 'module', 'orders', 'reports', 'sales','suppliers','receivings','giftcards', 'item_kits');

config.php

Code:

$config['language'] = 'en';

My /application/language/ folder structure hasn't changed and is a two character subfolder for each language with identical _lang.php files in each folder (e.g. /application/language/en/...)

again, this is working properly in 2.1.4.