According to documnetation the Zend/Filter/HtmlEntities must be use in this way:

Zend_Filter::filterStatic('"', 'HtmlEntities', array(ENT_QUOTES, 'UTF-8'));

but the __construct method is checking the arguments with the key which are not described in the guide: public function __construct($options = array()) { ... if (!isset($options['quotestyle'])) { $options['quotestyle'] = ENT_COMPAT; }

    if (!isset($options['charset'])) {
        $options['charset'] = 'ISO-8859-1';
    }

... }

Solution: - change the guide to Zend_Filter::filterStatic('"', 'HtmlEntities', array('quotestyle'=>ENT_QUOTES, 'charset'=>'UTF-8')); OR - change the __construct method to: public function __construct($options = array()) { ... if (!isset($options[0])) { $options[0] = ENT_COMPAT; }

    if (!isset($options[1])) {
        $options[1] = 'ISO-8859-1';
    }

... }

Thank you

Kind regards Oleg Demeshev