HomeFixesFix Firefox Browser Error SEC_ERROR_INADEQUATE_KEY_USAGE




So, imagine you’re browsing the web, trying to access a secure website, and suddenly, you’re faced with a cryptic error message: “SEC_ERROR_INADEQUATE_KEY_USAGE.” Not the most user-friendly thing to encounter, right?

Well, fear not! In this quick guide, we’ll break down what this error on Firefox browser means and, more importantly, how you can fix it on your Firefox browser.


We’ll demystify the jargon and provide straightforward steps to get back to your secure browsing experience without breaking a sweat. Let’s dive in and conquer this error together!

What’s the Firefox Browser Error SEC_ERROR_INADEQUATE_KEY_USAGE All About?

The “SEC_ERROR_INADEQUATE_KEY_USAGE” error is a mouthful, but it essentially boils down to a security issue related to SSL or TLS certificates. When you visit a website using the HTTPS protocol, your browser verifies the authenticity of the website’s certificate to ensure a secure connection.

This error occurs when the certificate’s key usage is insufficient to establish a secure connection. In short, it’s like trying to open a locked door with a key that doesn’t quite fit.

Reasons Behind this Error on Mozilla Firefox Web Browser

  • Mismatched Certificate: The website’s SSL/TLS certificate might not be configured correctly, lacking key usage extensions.
  • Expired or Invalid Certificate: An expired or improperly issued certificate can trigger this error.

How to Troubleshoot & Fix SEC_ERROR_INADEQUATE_KEY_USAGE Error on Firefox Browser

Image credit: Mozilla
  • Check Your System Clock: Believe it or not, an incorrect system clock can lead to certificate validation issues. Make sure your computer’s date and time settings are accurate.
  • Clear Cache and Cookies: Sometimes, cached data can interfere with the certificate validation process. Clear your browser’s cache and cookies, then try accessing the site again.
  • Update Firefox: Ensure you’re using the latest version of Firefox. Outdated browser versions might lack the necessary security updates to handle certificates correctly.
  • Disable Security Software Temporarily: Sometimes, third-party security software can conflict with Firefox’s certificate validation process. Temporarily disabling such software and attempting to access the site can help identify if it’s causing the problem.
  • Try a Different Browser: If the issue persists, try accessing the website from a different browser. This can help confirm if the problem is specific to Firefox.
  • Contact Website Support: If the error persists on Firefox but not on other browsers, the website’s certificate may be misconfigured. Contact the website’s support team to inform them of the issue.
  • Check Date and Time on Router: In some cases, your router’s date and time settings might be incorrect, causing the SSL/TLS validation to fail. Verify and adjust the settings if needed.

While the above steps should help you resolve the error, exercising caution and verifying the website’s authenticity is crucial before proceeding. Incorrectly configured certificates can indicate potential security risks, so ensure you’re dealing with a legitimate site.

With these steps, you’ll hopefully be able to bid farewell to the SEC_ERROR_INADEQUATE_KEY_USAGE error and get back to browsing securely on Firefox.



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