I try to install the live_agent module. When I go to enable the module, I get the following errors:

Notice: Use of undefined constant DRUPAL_ROOT - assumed 'DRUPAL_ROOT' in /sites/all/modules/live_agent/live_agent.module on line 319

Warning: require_once(DRUPAL_ROOT/includes/errors.inc) [function.require-once]: failed to open stream: No such file or directory in /sites/all/modules/live_agent/live_agent.module on line 319

Fatal error: require_once() [function.require]: Failed opening required 'DRUPAL_ROOT/includes/errors.inc' (include_path='.:/usr/share/pear:/usr/share/php') in /sites/all/modules/live_agent/live_agent.module on line 319

The code causing the error is the following one.

 /* 318 */ function live_agent_buttons_form(&$form_state) {
 /* 319 */   global $base_url;
 /* 320 */ 
 /* 321 */   $settings = new liveagent_Settings();
 /* 322 */   $la_buttons_grid = $settings->getButtonsGridRecordset();
 /* 323 */   $recordset = $la_buttons_grid->toArray();
 /* 324 */ 
             // ...
 /* 373 */ }

Any help on debugging this would be greatly appreciated.

  • Hello, and welcome to DA! If you read the code and the error message, you'll see that line 319 is not a require_once as the error message states, so you appear to have pasted the wrong code. Bugs in modules a considered off-topic for this site.
    – Letharion
    Feb 25, 2013 at 18:59
  • @Letharion I pasted the code that is at line 319 of the module file.
    – apaderno
    Feb 25, 2013 at 21:17
  • Do you have APC enabled? If so, try disabling it temporarily.
    – mpdonadio
    Feb 26, 2013 at 2:42
  • @kiamlaluno I see. Well, that combination of code and error message still doesn't seem to make sense to me. :)
    – Letharion
    Feb 26, 2013 at 7:09
  • @Letharion The errors seem caused from the autoload function, but I don't know why the error is for that line.
    – apaderno
    Feb 26, 2013 at 9:00

2 Answers 2


The error about the undefined constant DRUPAL_ROOT could be caused from the index.php file that is corrupted, or that is returned corrupted from APC, or similar extension. DRUPAL_ROOT is always defined when Drupal bootstraps.

 * Root directory of Drupal installation.
define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';

As for why the error message is reported for that module when a function that doesn't contain any reference to the constant is executed, I think that is caused from the autoload function Drupal registers, drupal_autoload_class(), which is trying to load the file containing the class.


Check your settings.php file. You might have either.

You set the wrong base URL, or maybe you did not set one and this module requires it.

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