How to Fix the DLG_FLAGS_SEC_CERT_CN_INVALID Error

Last updated on by Dionisie Gitlan
How to Fix the DLG_FLAGS_SEC_CERT_CN_INVALID Error

Encountering security certificate issues while browsing can be frustrating, especially when confusing error messages appear. One common problem users face is the DLG_FLAGS_SEC_CERT_CN_INVALID error, which disrupts browsing and causes concerns about the connection’s security.

Knowing how to fix the DLG_FLAGS_SEC_CERT_CN_INVALID error is important to ensure a smooth and safe online experience. This error can happen for different reasons, and fixing it quickly helps keep your data secure and maintain trust in the websites you visit.

What is the DLG_FLAGS_SEC_CERT_CN_INVALID Error?

The DLG_FLAGS_SEC_CERT_CN_INVALID error occurs when your browser detects a mismatch between the website’s security certificate and the domain name. This error code: dlg_flags_sec_cert_cn_invalid, is a security measure designed to protect you from potential threats such as phishing attacks or data interception.

When you encounter this error, the certificate presented by the website doesn’t match the URL you’re trying to visit. In simpler terms, the browser tells you something is off with the site’s security credentials.

This can happen when the website’s certificate is issued to a different domain name or if the certificate has expired or been tampered with. Browsers like Chrome, Firefox, and Edge will display this error to alert you before you proceed to the website.

What Causes the DLG_FLAGS_SEC_CERT_CN_INVALID Error?

You might face the DLG_FLAGS_SEC_CERT_CN_INVALID error due to an invalid or expired SSL certificate, an incomplete chain of trust, or an incorrectly configured SSL certificate.

These issues can prevent your browser from verifying the website’s identity, leading to security warnings. Let’s break down each potential cause to understand how they trigger this error.

  1. Expired SSL Certificate: SSL certificates have a set validity period. Once they expire, they can’t establish a secure connection, leading to this error.
  2. Mismatched Domain Names: The Common Name (CN) or Subject Alternative Name (SAN) in the SSL certificate must match the domain name exactly. If there’s a mismatch, browsers flag the certificate as invalid.
  3. Incomplete Chain of Trust: An incomplete certificate chain occurs when the web server doesn’t provide all necessary certificates. A full chain includes the end-entity certificate, intermediate, and root certificates. The missing intermediate certificates prevent browsers from verifying the SSL certificate properly.
  4. Incorrectly Configured SSL Certificate: Misconfigurations during the installation or setup of the SSL certificate can lead to this error. For example, mismatched common names, incorrect file paths, or permission issues can cause the certificate to be flagged invalid.

How to Fix the DLG_FLAGS_SEC_CERT_CN_INVALID Error?

To fix the DLG_FLAGS_SEC_CERT_CN_INVALID error, adjust your system’s date and time to ensure they’re correct. Next, empty your browser’s cache to remove any outdated certificates. If the issue persists, consider installing missing intermediate SSL certificates or another SSL certificate. As a last resort, turn off the certificate address mismatch option.

Correct the System’s Date & Time

To resolve the DLG_FLAGS_SEC_CERT_CN_INVALID error, one of the first steps is to ensure your system’s date and time settings are correct. Incorrect settings can make SSL certificates appear invalid because their validity periods won’t match your system’s clock.

For Windows:

  1. Right-click the clock in the taskbar.
  2. Select ‘Adjust date/time.’
  3. Ensure ‘Set time automatically’ and ‘Set time zone automatically’ are on.
  4. If the time is still incorrect, turn these settings off and manually set the correct date and time.
date and time

For Mac:

  1. Click the Apple menu and select ‘System Preferences.’
  2. Click ‘Date & Time.’
  3. Check ‘Set date and time automatically.’
  4. If the time is still incorrect, uncheck this option and set the time manually.
date and time on mac

Clear the Browser’s Cache

Another effective method is to clear your browser’s cache. Cached files can store outdated or incorrect SSL certificates, causing this error. Clearing the cache forces your browser to retrieve the latest security credentials from the server, which can resolve the issue.

To clear your browser’s cache:

Google Chrome

  1. Click the three-dot menu in the upper-right corner.
  2. Select ‘Delete browsing data.’

  3. Choose ‘All time‘ from the time range dropdown.
  4. Check ‘Cached images and files.’ and click ‘Delete data‘


Mozilla Firefox

  1. Click the menu button (three horizontal lines).
  2. Go to ‘Settings‘ > ‘Privacy & Security.’

  3. Under ‘Cookies and Site Data,’ click ‘Clear Data.’

  4. Check ‘Cached Web Content.’
  5. Click ‘Clear.’

Microsoft Edge

  1. Click the three-dot menu.
  2. Select ‘Settings‘ > ‘Privacy, search, and services.’

  3. Click ‘Choose what to clear.’

  4. Select ‘Cached images and files.’
  5. Close your browser ‘Clear now.’

After clearing the cache, restart your browser and try accessing the website again. This should help resolve the certificate error.

Install Missing Intermediate Certificates

  1. First, download the intermediate certificates from your SSL certificate provider’s website. They usually offer these files as part of their support resources.
  2. Once downloaded, open your web server’s configuration settings. The process varies depending on the server (Apache, Nginx, etc.), so refer to your server’s documentation for precise instructions.
    • On Apache, for instance, you’ll need to locate the SSL configuration file, named ssl.conf. Add the path to your intermediate certificate file using the SSLCertificateChainFile directive.
    • For Nginx, include the intermediate certificate in the ssl_certificate directive within your site’s configuration block.
  3. After making these changes, restart your web server to apply the new settings. Finally, use an SSL checker tool to ensure your certificate chain is correctly installed.

Use a Different SSL Certificate

When dealing with the DLG_FLAGS_SEC_CERT_CN_INVALID error, there’s a chance of a mismatch between the domain name in the SSL certificate and the actual domain you’re trying to access. To fix this, you’ll need a new SSL certificate that matches your domain name correctly.

  1. Choose a reliable reseller like SSL Dragon and one of the trusted CAs.
  2. Generate the CSR for your new SSL certificate.
  3. Specify the exact domain name, including subdomains, during the certificate request. For instance, yourdomain.com
  4. Upload the new SSL certificate files to your web server.
  5. Configure your web server to use the new certificate following one of our SSL installation guides.

Disable the Certificate Address Mismatch Setting

To address the DLG_FLAGS_SEC_CERT_CN_INVALID error, you can turn off the certificate address mismatch option in your browser settings. This option ensures that the website’s SSL certificate matches the URL you’re visiting. Disabling it can bypass the error when the certificate’s common name doesn’t align with the intended URL.

For Microsoft Edge:

  1. Open Edge.
  2. Type “Internet Options” in the Windows search bar and open it.
  3. Go to the “Advanced” tab.

  4. Scroll down to the “Security” section.
  5. Uncheck “Warn about certificate address mismatch.”
  6. Click “Apply” and “OK” to save your changes.

For Google Chrome and Mozilla Firefox:

As of 2024, Google Chrome and Mozilla Firefox do not offer a built-in option to disable the certificate address mismatch warning. It’s recommended to use a properly issued SSL certificate that matches your domain to resolve the error in these browsers.

Reset the Web Browser

Resetting your browser can help by restoring default settings and clearing any corrupt data. Here’s how to do it for Chrome, Firefox, and Edge.

Important Note: Resetting your browser will log you out of websites and erase saved preferences. Back up any important data before proceeding.

For Chrome

  1. Open Chrome.
  2. Type chrome://settings/reset into the address bar and press Enter.
  3. Click “Restore settings to their original defaults.”

  4. Confirm by clicking “Reset settings.”

For Mozilla Firefox:

  1. Open Firefox and click the three lines in the upper-right corner.
  2. Select “Help” and then “More troubleshooting information.”

  3. Click the “Refresh Firefox” button on the right side.

  4. Confirm by clicking “Refresh Firefox” again.

For Microsoft Edge:

  1. Open Edge and click the three dots in the upper-right corner.
  2. Select “Settings.”
  3. Click “Reset settings” on the left sidebar.

  4. Select “Restore settings to their default values.”

  5. Confirm by clicking “Reset.”


Conclusion

Seeing the error code: dlg_flags_sec_cert_cn_invalid can be frustrating, but it’s fixable with the right steps. By following the guide on how to fix the dlg_flags_sec_cert_cn_invalid error, you will have a secure browsing experience. Always keep your certificates up-to-date and correctly set up to avoid these issues. If problems continue, don’t hesitate to get professional help to keep your website secure and running well.

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