TypeError: string indices must be integers

[IngLP]

While using this plugin, like this:

certbot certonly \
    --authenticator certbot-plugin-cloudns:dns-cloudns \
    --certbot-plugin-cloudns:dns-cloudns-credentials /root/credentials.ini \
    $email_arg \
    $domain_args \
    --rsa-key-size 4096 \
    --agree-tos \
    --force-renewal

I get the following error:

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator certbot-plugin-cloudns:dns-cloudns, Installer None
Registering without email!
Obtaining a new certificate
Performing the following challenges:
dns-01 challenge for dev.gucci.aisolutions.technology
dns-01 challenge for gucci.aisolutions.technology
Cleaning up challenges
Encountered exception during recovery: 
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/certbot/_internal/auth_handler.py", line 70, in handle_authorizations
    resps = self.auth.perform(achalls)
  File "/usr/local/lib/python3.6/dist-packages/certbot/plugins/dns_common.py", line 57, in perform
    self._perform(domain, validation_domain_name, validation)
  File "/usr/local/lib/python3.6/dist-packages/certbot_cloudns/plugin.py", line 51, in _perform
    if zone['zone'] != 'domain':
TypeError: string indices must be integers

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/certbot/_internal/error_handler.py", line 125, in _call_registered
    self.funcs[-1]()
  File "/usr/local/lib/python3.6/dist-packages/certbot/_internal/auth_handler.py", line 243, in _cleanup_challenges
    self.auth.cleanup(achalls)
  File "/usr/local/lib/python3.6/dist-packages/certbot/plugins/dns_common.py", line 76, in cleanup
    self._cleanup(domain, validation_domain_name, validation)
  File "/usr/local/lib/python3.6/dist-packages/certbot_cloudns/plugin.py", line 82, in _cleanup
    response = self._get_cloudns_client().delete_record(self.records[validation_name]['zone'],
KeyError: '_acme-challenge.dev.gucci.aisolutions.technology'
An unexpected error occurred:
TypeError: string indices must be integers
Please see the logfiles in /var/log/letsencrypt for more details.

Any help?
Thanks