When i load the configuration page with the latest version of drupal 8, i've this error :
PHP Fatal error:  Call to undefined function Drupal\\captcha\\Form\\locale_language_list() in /home/desktop/s/drupal8/modules/captcha/lib/Drupal/captcha/Form/CaptchaSettingsForm.php on line 164


Hi, Thanks for the report. If you run into issues like this please check with https://drupal.org/list-changes.

There was a change https://drupal.org/node/1414264. If you could change the corresponding code and provide a patch that would be great.