Version 5.2.12 (Sep 1st 2015)

Version 5.2.12 (Sep 1st 2015)

html2text is removed due licensing issues
https://github.com/PHPMailer/PHPMailer/issues/232

however you can use callback now:

// Use your own custom converter
$plain = $mail->html2text($html, function($html) {
    $converter = new MyHtml2text($html);
    return $converter->get_text();
});

for example
https://github.com/soundasleep/html2text