Посмотрите логи в папке /var/log/docker_https_ДАТА.log
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator dns-cloudflare, Installer None
Obtaining a new certificate
Performing the following challenges:
dns-01 challenge for *domain*
dns-01 challenge for *domain*
Unsafe permissions on credentials configuration file: /cloudflare.ini
Cleaning up challenges
An unexpected error occurred:
KeyError: 'code'
Please see the logfiles in /var/log/letsencrypt for more details.