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Knowledge Base

Domain is not secured over WWW even though Let’s Encrypt certificate is installed

 
applications extensionsdomainshttpsplesk for linuxplesk for windows

Symptoms

  • Warning in browser is shown whenever the domain with installed Let's Encrypt SSL is accessed with www-prefix like https://www.example.com:

    NET::ERR_CERT_AUTHORITY_INVALID


    Your connection is not private
    This server could not prove that it is www.example.com; its security certificate is from example.com. This may be caused by a misconfiguration or an attacker intercepting your connection.

  • Certificates is shown "WWW domain not secured" under Domains > example.com >  SSL/TLS Certificates

Cause

The certificate was issued only for the domain example.com, without www-prefix.

Resolution

Reissue certificate with www-prefix:

  1. Login to Plesk;
  2. Open Domains > example.com > SSL/TLS Certificates
  3. Check the option Include a "www" subdomain for the domain and each selected alias
    mceclip1.png
  4. Click Reissue Certificate.
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