Subdomain suddenly giving certificate error

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My domain is:

I ran this command: open in browser (Chrome on laptop and mobile, Edge, Samsung Internet browser)

It produced this output:
This server could not prove that it is; its security certificate is from This may be caused by a misconfiguration or an attacker intercepting your connection.

My web server is (include version): Apache 2

The operating system my web server runs on is (include version): Debian 8.11 jessie

My hosting provider, if applicable, is: Bytemark

I can login to a root shell on my machine (yes or no, or I don't know): yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): n/a (Symbiosis?)

This subdomain has been in use for a couple of years with no problems, but now gives the error message as above. The main domain and other subdomains seem to be OK.

Let's debug gives the following output:

All OK!

No issues were found with If you are having problems with creating an SSL certificate, please visit the Let's Encrypt Community forums and post a question there.

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Hi @MikeGeorge

the result is expected, see your check, 10 minutes old -

The certificate
expires in 90 days - 1 entry

has only one domain name, is missing -> Grade N.

Your old certificate

Issuer not before not after Domain names LE-Duplicate next LE
R3 2020-12-12 2021-03-12 - 1 entries
Let's Encrypt Authority X3 2020-10-04 2021-01-02, - 2 entries

had both domain names, your new only one, so the non-www version isn't secure.

Create one certificate with both domain names.

Letsdebug doesn't check such existing certificate configurations.

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Thank you @JuergenAuer.

I've always relied on Symbiosis to install and renew my letsencrypt certificates and I don't know how this changed or how to put it right. I'll check the Bytemark documentation again, but any tips for correcting this would be very much appreciated!

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You have created the wrong certificate if you want to use the non-www version.

works, that's

the www version.

What's your client, what's your command? Add the non-www domain name.

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I'm not sure what you mean by client and command. All certificates on my server are generated automatically by Symbiosis and I've never created or edited one except with the symbiosis-ssl command.

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Then that command

is wrong or that tool has a wrong configuration.

So check the documentation of that tool.


that symbiosis-ssl may be your ACME-client.

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Bytemark Symbiosis

Bytemark Symbiosis

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Thanks @rg305, my server is on Debian 8.11 but I think the letsencrypt configuration is the same. I'll check in the morning.

This domain and a few others have been in use for a couple of years and previous automatic renewals of the certificates have been OK, so I've emailed Bytemark support to ask if there's been any change.


I'm afraid I don't have the technical knowledge to understand the solutions given here so I used the sledgehammer approach - I deleted all the config files for the domain and let Symbiosis rebuild them from scratch. The new certificate that was generated now covers the www and non-www variants.

Thank you for your help.


Then your config was buggy.

Individual, unknown ACME-client -> nobody knows how that works.

Happy to read you have found a solution. :+1:

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