Let's encrypt expired. Won't renew/reinstall. Says domain and IP cant be resolved?

I have a problem with my Let’s Encrypt SSL certificate on my Nextcloud 13.0.7 SNAP installation.
After a few months it now says that it has expired. I thought it would renew itself automatically…??
I have tried to renew the certificate without luck.
I now try to create a new with $ nextcloud.enable-https lets-encrypt.

It says that it can not resolve a domain name and there’s no valid IP address found for my domain.
All is set up in my router and my webhost and is working. I can connect through the domain name as I have been able to the last months… now I just have to “accept untrusted certificate” first.

How do I get this certificate renewed - heeeeeeeelp :))

Thank you in advance.

Snippet of letsencrypt.log:

2018-11-01 13:41:04,798:DEBUG:certbot.reporter:Reporting to user: The following errors were reported by the server:

Domain: cloud.hackerplace.dk
Type:   unknownHost
Detail: No valid IP addresses found for cloud.hackerplace.dk

To fix these errors, please make sure that your domain name was entered correctly and the DNS A/AAAA record(s) for that domain contain(s) the right IP address.
2018-11-01 13:41:04,799:DEBUG:certbot.error_handler:Encountered exception:
Traceback (most recent call last):
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 82, in handle_authorizations
    self._respond(aauthzrs, resp, best_effort)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 155, in _respond
    self._poll_challenges(aauthzrs, chall_update, best_effort)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 226, in _poll_challenges
    raise errors.FailedChallenges(all_failed_achalls)
FailedChallenges: Failed authorization procedure. cloud.hackerplace.dk (http-01): urn:ietf:params:acme:error:unknownHost :: The server could not resolve a domain name :: No valid IP addresses found for cloud.hackerplace.dk

2018-11-01 13:41:04,799:DEBUG:certbot.error_handler:Calling registered functions
2018-11-01 13:41:04,799:INFO:certbot.auth_handler:Cleaning up challenges
2018-11-01 13:41:04,800:DEBUG:certbot_nextcloud_plugin.webroot:Removing /var/snap/nextcloud/current/certs/certbot/.well-known/acme-challenge/7bmgFBqRZFot3nFCFJKbROSPLSgWGoNG10qGYa78b7w
2018-11-01 13:41:04,800:DEBUG:certbot_nextcloud_plugin.webroot:All challenges cleaned up, removing /var/snap/nextcloud/current/certs/certbot/.well-known/acme-challenge
2018-11-01 13:41:04,801:DEBUG:certbot.log:Exiting abnormally:
Traceback (most recent call last):
  File "/snap/nextcloud/9551/bin/certbot", line 11, in <module>
    sys.exit(main())
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/main.py", line 1364, in main
    return config.func(config, plugins)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/main.py", line 1254, in certonly
    lineage = _get_and_save_cert(le_client, config, domains, certname, lineage)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/main.py", line 115, in _get_and_save_cert
    renewal.renew_cert(config, domains, le_client, lineage)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/renewal.py", line 305, in renew_cert
    new_cert, new_chain, new_key, _ = le_client.obtain_certificate(domains, new_key)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/client.py", line 334, in obtain_certificate
    orderr = self._get_order_and_authorizations(csr.data, self.config.allow_subset_of_names)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/client.py", line 370, in _get_order_and_authorizations
    authzr = self.auth_handler.handle_authorizations(orderr, best_effort)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 82, in handle_authorizations
    self._respond(aauthzrs, resp, best_effort)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 155, in _respond
    self._poll_challenges(aauthzrs, chall_update, best_effort)
  File "/snap/nextcloud/9551/lib/python2.7/site-packages/certbot/auth_handler.py", line 226, in _poll_challenges
    raise errors.FailedChallenges(all_failed_achalls)
FailedChallenges: Failed authorization procedure. cloud.hackerplace.dk (http-01): urn:ietf:params:acme:error:unknownHost :: The server could not resolve a domain name :: No valid IP addresses found for cloud.hackerplace.dk

cloud.hackerplace.dk has address 192.168.0.103

you could try to assign a public ip address. 192.168. is private.