Fix lỗi dispatcher.php và event.php trên PHP 5.3 and higher

There are a few plugins that are not compatible with PHP 5.3+ and Joomla 1.5x, and they may show up like the error messages below:
Warning: Parameter 1 to plgContentJA_tabs:nPrepareContent() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentPlg_JAThumbnail:nPrepareContent() expected to be a reference, value given in home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentEmailCloak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentLoadModule() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentPagebreak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentJA_tabs:nPrepareContent() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentPlg_JAThumbnail:nPrepareContent() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentEmailCloak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentLoadModule() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentPagebreak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentJA_tabs:nPrepareContent() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentPlg_JAThumbnail:nPrepareContent() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/event.php on line 67
Warning: Parameter 1 to plgContentEmailCloak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentLoadModule() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136
Warning: Parameter 1 to plgContentPagebreak() expected to be a reference, value given in /home/bienthuy/public_html/libraries/joomla/event/dispatcher.php on line 136

It’s just a warning, so you can easy disable it by login to administrator, then go to configuration, click Server tab, and look at Error Reporting, choose None on the dropdown list. (As in below picture)

Or, if you dont want to do that, you can complete change some code to fix it work on PHP 5.3 or higher. Fortunately, this is a pretty simple thing to fix;

Step 1: Open dispatcher.php and find:

if (function_exists($observer['handler']))
{
   $result[] = call_user_func_array($observer['handler'], $args);
}

Replace by:

if (function_exists($observer['handler']))
{
   $args[1]   = & $args[1];
   $result[] = call_user_func_array($observer['handler'], $args);
}

Step 2: Open event.php and find:

if (method_exists($this, $event)) {
  return call_user_func_array ( array($this, $event), $args );
}

Replace by:

if (method_exists($this, $event)) {
  $args[1] = & $args[1];
  return call_user_func_array ( array($this, $event), $args );
}

Alternatively, you can download these fixed files Joomla dispatcher.php and event.php. Hope this helps!