# Troubleshoot datacenter server https error

## Setup

The datacenter server is maintained with Virtualmin.
The domain causing the problem is "kipurchat.creature-go.com".
The SSL certificate provider is Let's Encrypt.

## Problem

When trying to open "kipurchat.creature-go.com" the web browser shows this
error (first section and certificates cut out):

```
net::ERR_CERT_DATE_INVALID
Subject: kipurchat.creature-go.com

Issuer: R13

Expires on: 28.01.2026

Current date: 14.03.2026

Certificate Transparency:

SCT Google 'Argon2026h1' log (Embedded in certificate, Verified)

SCT Let's Encrypt 'Oak2026h1' (Embedded in certificate, Verified)
```

## First own troubleshooting

The Virtualmin webpage SSL Certificate
In domain kipurchat.creature-go.com
shows that renewal of the certificate failed:
"
SSL certificate providers like Let's Encrypt can be used to automatically request a valid cert for use by Virtualmin.
This page can be used to request a new certificate, which will overwrite any other you currently have configured for this domain. However, SSL certificate providers require that your ownership of the certificate domain be validated by checking that this system hosts the website for the domain. This is done by placing a small temporary file under the website's document directory /home/admincg/domains/kipurchat.creature-go.com/public_html.


Request certificate for

  Domains associated with this server 
kipurchat.creature-go.com

  Domain names listed here 

   Also request wildcard certificate? 
SSL certificate provider
Let's Encrypt
Automatically renew certificate

  Yes 
 
  No 
Send email on renewal

  Yes 
 
  Only on failure 
 
  No 
Hostname verification

  Attempt to request all hostnames, and fail if any cannot be validated 


  Skip unresolvable hostnames, but fail if any remaining cannot be validated 


  Exclude hostnames that cannot be validated from the certifcate 
Certificate hash type

RSA
Time since last renewal
0.00 months
Last failed renewal
03/14/2026 11:39 AM
Renewal failed due to
Web-based validation failed :
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Renewing an existing certificate for kipurchat.creature-go.com
An unexpected error occurred:
AttributeError: can't set attribute
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.
   DNS-based validation failed :
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Renewing an existing certificate for kipurchat.creature-go.com
An unexpected error occurred:
AttributeError: can't set attribute
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.
"

## Your tasks

Please help me by running these tasks:

### Understand the root cause

Why did the certificate renewal fail?

### Repair the SSL certificate setup

Change the SSL certificate setup so that future renewals will work.

### Repair SSL connection

If not already done by completing the task before, repair the SSL connection so that "kipurchat.creature-go.com" can be used again.