The SEC_ERROR_BAD_SIGNATURE error in Firefox prevents users from accessing websites on the browser. Since it is a browser-specific error, you might be able to access the website on other browsers. Before proceeding to any solution, it is necessary to verify whether the website is genuine or not by opening on another reliable browser (e.g. Chrome or Edge) and checking it out.
SEC_ERROR_BAD_SIGNATURE error in Firefox
If the website works fine with other browsers, the issue while opening it on Firefox could be caused by interference by an extension or an anti-virus. Other than this, proxy settings on your browser might be preventing you from accessing the website.
- Clear the cookies and cache files for Firefox
- Turn off the Firewall and third-party anti-virus programs temporarily
- Launch Firefox in Safe Mode
- Remove Proxy settings from your Firefox browser
You can try the following solutions sequentially to resolve the problem:
1] Clear the cookies and cache files for Firefox
Before proceeding to further solutions, you could try clearing cookies and cache files for Firefox.
Click on the Library button and select History from the menu.
Click on Clear recent history.
Make sure that the checkboxes corresponding to cookies and cache are both selected and then change the Time range to Everything.
Now click on Clear now to delete the cookies and cache.
Basically, the cache files store information associated with a website when you open it for the first time. It is stored as offline data and makes it quicker to open the website for further sessions. However, if the cache files are corrupt, it the error in the discussion would appear, thus preventing you from accessing the website.
2] Turn off the Firewall & third-party anti-virus programs temporarily
Many third-party anti-virus programs are known to falsely flag genuine programs and websites as malicious and block them. The same is the case with the Windows Defender Firewall. To isolate this cause, you could temporarily disable the Windows Defender Firewall and the third-party anti-virus software installed on your system.
3] Launch Firefox in Safe Mode
The Safe Mode in Firefox is the mode in which the add-ons are disabled. Since one of the causes of the issue is troublesome extensions, you could try launching Firefox in Safe Mode to isolate this cause.
Open Firefox and click on the Menu button.
Select Help > Restart with Add-ons Disabled.
This would launch Firefox in Safe Mode. Try opening your website. If it works fine in Safe Mode, you would have to find and delete the troublesome extension.
To check the list of extensions, open the address about:addons on the Firefox browser and go to the Extensions tab. You could delete troublesome extensions from there.
4] Remove Proxy settings from your Firefox browser
The Proxy settings on your browser could prevent you from accessing certain websites by causing the SEC_ERROR_BAD_SIGNATURE error. You could change them as follows:
Click on the Menu button on the Firefox browser and select Options or enter about:preferences in the address bar.
In the General section, scroll down to Network Settings and click on Settings.
Now shift the radio button for Configure Proxy Access to the Internet to No proxy.
Hit OK to save the settings.
The solutions mentioned above should be helpful in resolving the SEC ERROR BAD SIGNATURE error in Firefox.