Error 0004

from UPDATE `wp_mlw_questions` SET `question_name` = ‘* Acconsento al trattamento dei dati secondo la <a href="http://www.form-action.it/#">normativa sulla privacy</a>’, `answer_array` = ‘a:0:{}’, `question_answer_info` = ”, `comments` = 1, `hints` = ”, `question_order` = 8, `question_type_new` = ‘8’, `question_settings` = ‘a:1:{s:8:”required”;i:0;}’, `category` = ” WHERE `question_id` = 4