# Certificate problem

**URL:** <https://community.traefik.io/t/certificate-problem/12605>\
**Category:** Traefik v2\
**Tags:** docker\
**Created:** [December 2, 2021, 11:59pm UTC](https://community.traefik.io/t/certificate-problem/12605 "2021-12-02T23:59:55Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![erth5](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/erth5/32/4564_2.png) [@erth5](https://community.traefik.io/u/erth5)\
**Post date:** [December 2, 2021, 11:59pm UTC](https://community.traefik.io/t/certificate-problem/12605/1 "2021-12-02T23:59:55Z")

</div>

I want to give traefik my lets encrypt certificate. My url is registered (I use a subdomain test.domain from united domains) and the certificate is valid. Port 80 on my server is open. But ACME response:

time="2021-12-02T23:49:59Z" level=error msg="Unable to obtain ACME certificate for domains "[test.url.com](http://test.url.com)":  
unable to generate a certificate for the domains [[test.url.com](http://test.url.com)]: error: one or more domains had a problem:  
\n[[test.url.com](http://test.url.com)] acme: error: 400 :: urn:ietf:params:acme:error:connection ::  
Timeout during connect (likely firewall problem)\n" rule="Host(`test.url.com`)  
&& (PathPrefix(`/api`) || PathPrefix(`/dashboard`))" providerName=letsencrypt.acme  
routerName=traefik@docker

why