Error: SSL Certificate Not Trusted / SEC_ERROR_UNKNOWN_ISSUER

Status Code: SEC_ERROR_UNKNOWN_ISSUER / ERR_CERT_COMMON_NAME_INVALID / NET::ERR_CERT_AUTHORITY_INVALID

Impact: Browsers display a full-page security warning block, preventing visitors from viewing the site over HTTPS.

Quick Diagnostic Overview

Browser Request -> Host Domain -> SSL Handshake Check (FAIL: Mismatched Name / Missing Chain) -> Security Warning Block

Direct Error Identifiers & Solutions

1. SSL Domain Name Mismatch (ERR_CERT_COMMON_NAME_INVALID)

• Error Trigger: The active SSL certificate was issued for a different domain or is missing the www subdomain variant.

• Root Cause: The domain is attempting to serve a default fallback certificate (like a hostname or shared server certificate) instead of a dedicated certificate for the specific domain name.

• Immediate Fix:

  1. Open your hosting control panel and navigate to the SSL/TLS Manager.
  2. Verify that an active certificate is bound specifically to yourdomain.com AND [www.yourdomain.com](https://www.yourdomain.com).
  3. Re-issue or run an auto-SSL check to generate a fresh certificate covering all domain aliases.

2. Incomplete CA Bundle / Missing Intermediate Chain (SEC_ERROR_UNKNOWN_ISSUER)

• Error Trigger: Browsers (especially mobile devices and Safari/Firefox) report an untrusted certificate authority.

• Root Cause: The main domain certificate was installed, but the Intermediate Certificate Authority (CA Chain) bundle was omitted during manual installation.

• Immediate Fix:

  1. Open the SSL/TLS Certificate Installation tool in your control panel.
  2. Paste your primary CRT certificate file into the main certificate block.
  3. Ensure the CABUNDLE / Intermediate Certificate text box is populated with the CA chain provided by your certificate issuer before saving.

3. Mixed Content Warnings (NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED)

• Error Trigger: The padlock shows an exclamation point or yellow warning icon instead of a green/closed padlock.

• Root Cause: The site is loading securely over https://, but hardcoded internal resources (images, CSS scripts, or external JS files) are still using insecure http:// paths in the source code.

• Immediate Fix:

  1. Open the page in your browser, right-click, and select Inspect Element → Console.
  2. Filter logs by Mixed Content.
  3. Update absolute links in your code or database from [http://yourdomain.com/](http://yourdomain.com/)... to [https://yourdomain.com/](https://yourdomain.com/)... or relative paths /....

Need Further Assistance?

• Hosting Environment Check: If your domain DNS is pointed to GaugeHosting.com and automated SSL provisioning fails to trigger, open a ticket in your client portal under Support for quick server-level certificate verification.
• Website Code & SSL Remediation: If your site suffers from deep mixed-content warnings, broken database paths, or complex SSL redirect loops, contact the technical development team at Horizon Web Services to audit and clean up your site architecture.