How to Resolve the SEC_ERROR_BAD_SIGNATURE in Firefox

Here we can see, “How to Resolve the SEC_ERROR_BAD_SIGNATURE in Firefox”

Web browsers only have two real competitors: Firefox and Google Chrome. Mozilla Firefox is an open-source web browser created by Mozilla Corporation. The constant upgrades make the browser more stable, faster, and more secure. However, there are some difficulties with Mozilla Firefox. Secure Connection Failed (SEC_ERROR_BAD_SIGNATURE) in Firefox prevents you from visiting websites that other browsers can access.

This issue appears to be caused by your system’s apps or web browser extensions. Other than that, your browser’s network settings can cause the issue. The error code isn’t scary, and the remedies to the error code are simple and quick. So let’s get started.

What causes SEC_ERROR_BAD_SIGNATURE in Firefox?

The error notice can prevent you from accessing websites like Facebook, etc. This issue can be caused by:

  • Common Cause: Third-party antivirus software on your machine. Such software frequently restricts your access to particular websites.
  • Firefox Extensions: The extensions you have installed can also cause issues. One of them may be interfering with certifications, resulting in the error notice. Start Firefox in Safe Mode to remedy this.
  • Your Firefox Network settings may also cause the error notice. Using a proxy may be creating the issue.
  • So let’s get to the solutions: Some solutions may not work for you since that element does not cause your issue. So kindly follow them all to achieve a rapid resolution.


Solution 1: Disable Third-Party Antivirus

When you get the error warning, turn off any third-party antivirus software on your system. Antivirus software frequently restricts your system’s web connectivity, preventing you from accessing specific websites. So, disable your antivirus software, exit your browser, and see if that helps.

If it works, you will need to add an exception in your antivirus for Firefox’s Network settings.

Solution 2: Start Firefox in Safe Mode.

Your browser’s extensions can potentially interfere with specific connections and certificates, causing difficulties. Launch Firefox in Safe Mode, which disables all extensions and resets the browser to factory defaults. If it helps, you’ll need to uninstall the extensions one by one until you find the problem. Start Firefox in safe mode:

  1. Fire up Firefox.
  2. Activate “Restart with Add-ons Disabled” by clicking the menu button in the top right corner.
  3. Firefox now starts in Safe Mode.

Solution 3: Changing Network Settings

You can also adjust your Firefox’s Network options. If you don’t use a proxy, you should disable it in Firefox. If you do, compare it to other web browsers. How to turn off Proxy:

  1. Fire up Firefox.
  2. Select Options from the menu button.
  3. Scroll down to Network Settings under General.
  4. Go to Settings.
  5. No Proxy, click OK.
  6. Close the Tab to save changes.
  7. Reopen Firefox.
  8. See if that helps.


User Questions:


The page you requested could not be shown due to insufficient data authentication. SEC_ERROR_BAD_SIGNATURE The requested page could not be shown due to insufficient data authentication.

In Firefox, how to fix certificate failures

  1. Click Tools > Options > Advanced tab.
  2. Select Encryption.
  3. Click View Cert.
  4. Go to Servers.
  5. Find z/OSMF CertAuth in the Certificate Name column.
  6. Delete the certificate files under z/ OSMF.
  7. OK.

How do I secure a connection in Firefox?

  1. Verify Date and Time. Our web browsers and PCs employ security certificates to ensure a site is safe.
  2. Clearing the Browser’s History.
  3. Reload the Website.
  4. Using self-signed certificates in Firefox
  5. to Privacy & Security, then View Certs.
  6. Servers Tab> Add Exception
  7. verify that Save this Exception is enabled.
  8. Confirm Security Exception



The UNKNOWN ISSUER notification usually suggests a “man in the middle” of Firefox and the website. Your parental controls or security software could be harmless, or it could be malware or a suspicious government.

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