Thread:Extension talk:ConfirmEdit/PHP Fatal error: Class 'HTMLFormField' not found in /var/www/vhosts/.../httpdocs/extensions/ConfirmEdit/HTMLCaptchaField.php on line 22/reply (2)

Then, why does the Extension page state the current release of ConfirmEdit supports MW 1.11 and later? I'm having the same problem, on a MW 1.15-based system.