This mostly happens after updating php to 5.3.X

You need to edit file named :   database.php which will be under includes folder  and add

EG :  /home/username/public_html/includes/database.php

===========================================================================

/** @var mosDatabase Database connector */
var $_db = null;

// ADD THIS FUNCTION….
    function mosDBTable($table=”, $keyname=’id’, $db=”) {
        $this->mosDBAbstractRow ($table, $keyname, $db);
}

===========================================================================

If it still shows a warning in some lines like :  /home/username/public_html/includes/Cache/Lite/Function.php

Edit the error line mentioned and add that as below :

line 100:
$result = call_user_func_array($target, $arguments);
to
$result = call_user_func_array($target, &$arguments);