libraries_get_path does not in coder_upgrade\includes\settings.inc on line 34

Firstly, thank you to all the hard work you do on Drupal!

Despite trying with all the latest code, I get the following error (on my localhost installation):

Fatal error: require_once() [function.require]: Failed opening required 'C:\ProgramData\Apache Group\www\chess_drupal_7//engine/parser.inc' (include_path='.;C:\php5\pear') in C:\ProgramData\Apache Group\www\chess_drupal_7\sites\all\modules\coder\coder_upgrade\includes\settings.inc on line 34

The actual code at this line is:

require_once DRUPAL_ROOT . '/' . libraries_get_path('grammar_parser') . '/engine/parser.inc';

As a workaround I have hard-coded my path as follows:

require_once DRUPAL_ROOT . '/' . 'sites/all/modules/grammar_parser' . '/engine/parser.inc';

I have tried with all the latest code:
Coder Upgrade 7.x-1.x-dev
Grammar Parser 7.x-1.2
Grammar Parser Library 7.x-1.x-dev
Libraries 7.x-2.x-dev

Let me know if I can be any help.