To solve- Warning: Parameter 1 to modMainMenuHelper::buildXML() expected to be a reference…

To solve- Warning: Parameter 1 to modMainMenuHelper::buildXML() expected to be a reference, value given in /libraries/joomla/cache/handler/callback.php on line 99

I have spent 3 difficult weeks trying to solve an error with Joomla. I recently moved 5 websites from two different servers. The new server did not display any menus. Apparently error reporting was turned off.

I loaded it on my localhost and got the “Warning: Parameter 1 to modMainMenuHelper::buildXML() expected to be a reference, value given in /libraries/joomla/cache/handler/callback.php on line 99” errors (see screenshot).

Here is the solution:

The site currently runs on Joomla 1.5. The previous server ran PHP 5.2.9 while the new server ran a later version of PHP, 5.3.0. This error is thrown because of the reference type used in the helper file.

Locate modules/mod_mainmenu/helper.php, open the file and change the following line from

function buildXML(&$params)

to

function buildXML($params)

Viola! You have your menus back.

I will warn you though, you have to upgrade to the latest version of Joomla.