Error: Let's Encrypt acc registration failed 400

Community Support Install & Set-Up
1

I didn’t find any answer to my problem, so I try it here. I have a fresh hestiaCP installation, I added a user in the Linux command line and a domain in hestiaCP control panel. Now I want to add a Let’s Encrypt SSL Certificate to the domain and I get the error “Error: Let's Encrypt acc registration failed 400”.

The domain was using previously a Let’s Encrypt SSL Certificate with the Cloudflare API for years without any problem [under Plesk]. I have disabled the firewall with ufw disable and it’s also shown as disabled in the hestiaCP control panel.

I tried to follow the steps in SSL Certificates | Hestia Control Panel , but in the log file /var/log/hestia/LE-hestiaCP-****.log there is no ==[Step 5]==. This is the only one content:

=============================
Date Time: 2026-05-07 17:06:02
WEB_SYSTEM: apache2
PROXY_SYSTEM: nginx
user: hestiaCP
domain: *******

What is the problem?

I tried v-add-letsencrypt-host and I get this output:

/usr/local/hestia/bin/v-add-letsencrypt-user: line 96: xxd: command not found
/usr/local/hestia/bin/v-add-letsencrypt-user: line 102: xxd: command not found
Error: Let’s Encrypt acc registration failed 400
Error: Let’s Encrypt SSL creation failed

So, it looks like it fails because xxd is not found. I am investigating further what xxd should be.

2

Did you try to get a certificate multiple times?

Show the output of this command (replace YourUser with the actual name):

ls -la /usr/local/hestia/data/users/YourUser/ssl/

Show also the output of this command:

curl -s -I https://acme-v02.api.letsencrypt.org/directory
3

The reason was indeed the missing of the executable xxd. After installing it with apt-get install xxd the certificate has been installed successfully and opening it in a browser shows a valid certificate. Strange, that xxd was not installed….