Firefox Edge Browser Error Code SEC_ERROR_OCSP_INVALID_SIGNING_CERT: How to Fix It

Medium 10-30 minutes Medium Severity Verified June 2026
Summarize with ChatGPTSummarize with ClaudeSummarize with Perplexity Add as Preferred Source on Google
Error Code
SEC_ERROR_OCSP_INVALID_SIGNING_CERT
Brand
Firefox Edge
Product Type
browser
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
10-30 minutes
The SEC_ERROR_OCSP_INVALID_SIGNING_CERT error in Firefox means the browser attempted to verify a website's SSL certificate using OCSP (Online Certificate Status Protocol), but the certificate used to sign the OCSP response was not trusted or was invalid. This typically happens due to a corrupted certificate database, incorrect system date/time, overly aggressive antivirus SSL scanning, or a misconfigured network device intercepting your traffic. The error is a security protection mechanism — Firefox is warning you that something in the certificate verification chain does not look right.
Ad

Tools You'll Need

How to Fix Error Code SEC_ERROR_OCSP_INVALID_SIGNING_CERT

  1. Check and Correct Your System Date and Time

  2. Reload the Page and Clear Firefox Cache

  3. Delete and Rebuild Firefox's Certificate Database

    Do not delete cert9.db outright until you confirm the rename fixed the issue. Renaming it creates a safe backup you can restore if needed.

  4. Disable OCSP Stapling Temporarily to Diagnose

    Disabling OCSP reduces your browser's ability to detect revoked certificates. Only disable it temporarily for testing and re-enable it promptly.

  5. Check Antivirus or Security Software SSL Scanning

    Disabling SSL scanning in your antivirus reduces real-time web threat detection. Only disable it temporarily to diagnose; re-enable it or configure an exclusion once confirmed.

  6. Check for Network Interception (Proxy, VPN, Corporate Firewall)

  7. Update Firefox to the Latest Version

  8. Refresh Firefox (Reset to Default Settings)

    The Firefox Refresh will remove all installed extensions, custom settings, and open tabs. Your bookmarks, saved passwords, and browsing history are preserved.
Ad

When to Call a Professional

If you are on a corporate or managed network and the error persists after all steps, contact your IT department — they control the network certificates and SSL inspection policies that Firefox must trust. If the error only affects one specific website (not all HTTPS sites), the problem may be with that website's server certificate configuration, and the site owner or their hosting provider needs to fix it. If you suspect a security compromise or man-in-the-middle attack on your network, contact a cybersecurity professional immediately rather than bypassing the error.

Frequently Asked Questions

Is SEC_ERROR_OCSP_INVALID_SIGNING_CERT dangerous to ignore?
You should not casually ignore this error. It means Firefox cannot verify whether the website's certificate has been revoked, which could indicate a security problem. However, false positives do occur due to antivirus SSL scanning, VPNs, or a corrupted certificate database. Work through the troubleshooting steps to find the root cause before deciding to bypass the warning.
Why does this error only appear in Firefox and not Chrome or Edge?
Firefox uses its own built-in certificate store and its own OCSP validation logic, independent of the Windows or macOS system certificate store. Chrome and Edge typically rely on the operating system's certificate store and may handle OCSP differently. This is why antivirus-injected certificates or corporate SSL inspection certificates that are trusted by the OS may still cause errors in Firefox.
Can a wrong system date or time really cause SEC_ERROR_OCSP_INVALID_SIGNING_CERT?
Yes, absolutely. OCSP responses include timestamps and validity windows. If your computer clock is significantly off — even by a day or more — Firefox may determine that an OCSP signing certificate is expired or not yet valid, triggering this exact error. Always check your system time first as it is the quickest fix to rule out.
How do I add my antivirus certificate to Firefox so HTTPS scanning works without errors?
Go to Firefox Menu > Settings > Privacy & Security > scroll down to Security > click 'View Certificates'. In the Authorities tab, click 'Import' and browse to your antivirus program's root certificate file (usually found in the antivirus installation folder or documented in their support guides). Check the box to trust the certificate for websites, then click OK. Restart Firefox. Many antivirus programs also have a built-in option to automatically add their certificate to Firefox — check your antivirus documentation for this setting.
Will refreshing Firefox delete my saved passwords and bookmarks?
No. The Firefox Refresh feature is designed to preserve your bookmarks, saved passwords, browsing history, and open tabs (stored in a recovery file). However, it will remove all installed extensions, themes, customized settings, and site-specific permissions. After refreshing, you will need to reinstall any extensions you use and re-apply any custom browser settings.

Related Error Codes