[SOLVED][Drupal Errors] [Drupal 6] Fatal error: Unsupported operand types in common.inc

The cause of the error lies with the fact that Drupal modules containing the url() function which have been ported from Drupal 5 to Drupal 6 did not completely follow the new standards set in Drupal 6 for the url() function. To locate the modules which have the sick code we need to do the following steps.

• Go to
  

  /includes/common.inc

• Locate the url() function
• Change the following code in the function from
  

  <?php
  function url($path = NULL, $options = array()) {
    // Merge in defaults.
    $options += array(
      'fragment' => '',
      'query' => '',
      'absolute' => FALSE,
      'alias' => FALSE,
      'prefix' => ''
    );
  ?>

  to the following

  <?php
  function url($path = NULL, $options = array()) {
    if (!is_array($options)) {
      echo "&lt:pre>";
      $backtrace = debug_backtrace();
      var_export($backtrace[0]);
      die();
    }
    // Merge in defaults.
    $options += array(
      'fragment' => '',
      'query' => '',
      'absolute' => FALSE,
      'alias' => FALSE,
      'prefix' => ''
    );?>

• This will ensure that instead of an error you will get an array like the one shown below

array (
  'file' => '/www/drupal-6/sites/all/modules/admin_links/admin_links.module',
  'line' => 65,
  'function' => 'url',
  'args' => 
  array (
    0 => 'node/62/edit',
    1 => NULL,
    2 => NULL,
    3 => true,
  ),
)

• The file line will give a clue to which module is the culprit.
• Once you have located the module go the module's issue queue to see if anyone has reported the issue.
• Otherwise file a bug report so that the maintainer can fix the problem.

Hope that helps.