CiviCRM Community Forums (archive)

I am hoping that someone who knows the civi code can help me back track an error that I'm working on.
The Situation:

PHP throws a fatal error when ever the Save button is selected on CiviCRM » Administer CiviCRM » Global Settings  » Resource URLs if the Yes radio button is selected for Force Secure URLs (SSL).  This results in an HTML response code of 500 rather than the code 200 civi is looking for.

The error results, not in civiCRM, but in the core Joomla script /administrator/components/com_cpanel/admin.cpanel.php, line 17 which reads:

require_once( JApplicationHelper::getPath( 'admin_html' ) );

JApplicationHelper::getPath should return the path to a specific file on the site. The function is defined as:

function getPath( $varname , $user_option = null )

Param: $varname
$varname tells Joomla where you want to look in this component
Note: If no $user_option is specified, $user_option will default to "com_<component name>", "mod_<module name>", or <plugin name> depending on if you are using this method from a component, module, or plugin.

The admin_html parameter is defined as:

admin_html: returns the path to the component's main admin html file
Scope: Admin Only
root / administrator / components / $user_option / admin.<component name>.html.php

This script does not normally throw an error, as it is run every time the Admin control panel loads in the Joomla backend.

Why it fails:
In order to discover what missing file was causing require_once to fail, I inserted the following debug code into  admin.cpanel.php just before the offending line and re-executed the Save on Resource URLs:
<?php // php tag added here to get BB code syntax formatting.  Not present at this point in debug code.
// debug code begins
$problem_file = JApplicationHelper::getPath( 'admin_html' );
$f = fopen("/public/www/htdocs/administrator/debug.txt", "a"); 
if ($problem_file != NULL) {
  fwrite($f, $problem_file); 
} else {
  fwrite($f, "problem_file is null");
}
fclose($f);
// debug code ends

The debug.txt file read: problem_file is null

My Question:
What's the next step up the logic chain?  What is civi calling that is causing this script to load so that I can find out why the value is null?