Knowledge base article

Unable to renew certificate: The Let’s Encrypt HTTP challenge failed

This article will help you troubleshoot and resolve The Let's Encrypt HTTP challenge failed error from Let's Encrypt

The error can be identified by the following error/notification:

Unable to renew certificate: The Let's Encrypt HTTP challenge failed: acme error 'urn:acme:error:unauthorized'

You may receive this error for any of the following reasons:

Permissions Issue

Let's Encrypt may not have the correct permissions to access the required directories or files. You can check your permissions via the File Manager function in cPanel or using an SFTP client.

Within your public_html directory, make sure that the files ~public_html/.well-known and ~public_html/.well-known/acme-challenge both have the permission set to 755.

Conflicting Redirect Rule

Ensure there isn't a conflicting redirect rule adjusting your URL structure. Usually you can identify your configured redirects by viewing your .htaccess file.

To resolve this, you can add an exception so Let's Encrypt can access .well-known, this can be achieved by adding a rewrite condition like below into your .htaccess file:

# Allow .well-known through for Let's Encrypt.
RewriteCond %{REQUEST_URI} !^/.well-known/acme-challenge/

Please be aware the build of every website is different so although this code has worked for our support team previously, it has not always been successful. Serversaurus is not responsible for any unwanted interaction, it is up to you or your developer to understand how this code will interact with your website and if required, modify to be compatible with your website.

Domain is hosted externally

You can't issue a certificate for a domain that is hosted externally. Check which domains you are trying to issue the certificate for, if your website is hosted with Serversaurus but your mail services are hosted elsewhere, you will have to exclude from the certificate before attempting the certificate installation.

Last updated November 30, 2023

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