# Certbot Challenges failed, invalid response from

**URL:** <https://community.letsencrypt.org/t/certbot-challenges-failed-invalid-response-from/143226>\
**Category:** Help\
**Created:** [January 20, 2021, 7:35pm UTC](https://community.letsencrypt.org/t/certbot-challenges-failed-invalid-response-from/143226 "2021-01-20T19:35:42Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![JuergenAuer](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/juergenauer/32/26491_2.png) [@JuergenAuer](https://community.letsencrypt.org/u/JuergenAuer)\
**Post date:** [January 20, 2021, 8:28pm UTC](https://community.letsencrypt.org/t/certbot-challenges-failed-invalid-response-from/143226/4 "2021-01-20T20:28:16Z")

</div>

> [@HarrisonTrue](#):
>
> There is no machine with nginx though.

Please check that url. That's the url Letsencrypt checks to validate your domain. There is a nginx.

Read required basics:

> **[How It Works - Let's Encrypt](https://letsencrypt.org/how-it-works/)**
>
> The objective of Let’s Encrypt and the ACME protocol is to make it possible to set up an HTTPS server and have it automatically obtain a browser-trusted certificate, without any human intervention. This is accomplished by running a certificate...

PS:

> # 404 Not Found
> 
> nginx

I don't think that's the output of your IIS.

PPS: There is a check of your domain, ~~3,5 hours old - [https://check-your-website.server-daten.de/?q=ht930.com#url-checks](https://check-your-website.server-daten.de/?q=ht930.com#url-checks)

Same:

> [http://ht930.com/](http://ht930.com/)  
> 148.72.215.11  
> Server: nginx  
> Date: Wed, 20 Jan 2021 17:08:07 GMT

Only nginx - answers.

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