# How to Fix SEC_ERROR_BAD_SIGNATURE in Firefox **URL:** https://www.compsmag.com/blogs/how-to-fix-sec_error_bad_signature-in-firefox/ **Author:** Ayushi Chauhan **Published:** 2023-02-06 **Updated:** 2023-02-06 **Categories:** Blogs **Tags:** Android Guides, Apple Guides, Blogs Daily, Facebook tips and tutorials, Google tips and tutorials, guiderobert, Guides and Tutorials, guiding12, How To Guide, How To Guides, internet tips and tutorials, iphones guides, Originals How to, Social tips and tutorials, Software tips and tutorials, Tips, Tricks **Reading Time:** 6 min --- [Web browsers](https://compsmag.com/best/web-browsers/) like Mozilla Firefox are all that are needed to access the internet. One can access information in the forms of text, audio, images, and videos from all over the world using a web browser. In 2002, the Phoenix community helped the Mozilla Foundation create [Mozilla Firefox](https://compsmag.com/best/mozilla-firefox-extensions/). As a result of its derivation from Mozilla Web Browser, it is now only referred to as Firefox. Mozilla Firefox can be used to browse on [iPhone](https://compsmag.com/best/iphones/) and [Android phone](https://compsmag.com/best/android-phone/) as well. With its add-ons, security, and speed, Firefox gave Microsoft’s Internet Explorer fierce competition when it was formally released in November 2004. The speed of Mozilla Firefox is well-known. Even so, the Firefox browser requires a lot of memory to function properly. It might restrict [computers](https://compsmag.com/best/computers/)‘ ability to perform multiple tasks. It does, however, offer better network security. It has sophisticated security features that shield your computer from malware and spyware. It is secure from potential attackers using any unauthorized codes thanks to strong popup broker and authentication protocols. Users can also use enhanced security features like NoScript and Flashblock to further increase security. Users are unable to access websites using Firefox due to the SEC ERROR BAD SIGNATURE error. You might still be able to access the website on other browsers because the issue is browser-specific. It is necessary to confirm the legitimacy of the website by opening it in a trustworthy browser before moving on to any solutions. Occasionally, the error code “sec error bad signature” will appear in Firefox. Only when you are aware of the precise cause can you see the error’s solution. We mentioned below are the ways to Fix SEC_ERROR_BAD_SIGNATURE in Firefox. ## Ways to Fix SEC_ERROR_BAD_SIGNATURE in Firefox ### Open Browser in Safe Mode Launch Firefox. Select the button with three horizontal lines to display the application menu in the upper right corner. Select “Help” from the menu that appears. In the Firefox Help menu, click “Troubleshooting Mode…” in the Firefox Help menu. Firefox will ask you if you want to restart Firefox in troubleshooting mode, click the “Restart” button. Click the “Restart” button. Next, in the window that asks if you want to open the browser in troubleshooting mode, click the Open button. The browser will restart in Safe Mode with all extensions and custom settings disabled. Check to see if the problem has been resolved. ### Disable Third-Party Antivirus Many users have discovered that third-party security [software](https://compsmag.com/best/free-software/) prevents access to websites by preventing your system from connecting to the internet. Find the option to disable your [antivirus software](https://compsmag.com/best/antivirus-software/) by opening it. Once the antivirus programme has been turned off, launch your browser again and see if you can access the websites without encountering any problems. If this works for you, your antivirus program’s network configuration needs to include an exclusion. ### Change Installed Certificate Trust Settings Start the Firefox browser and type “about:preferences” in the address bar to open “Settings”. Follow the steps below to clear your browser history. Type “history” in the search box. Scroll down to “history” and click the “clear history” button. In the “Clear All History” window, select “All” in the drop-down associated with the time range to be cleared. Check all boxes in the History and Data section. Click OK. Once the history is cleared, return to the “Settings” screen. Select the “Privacy and Security” tab. Scroll down to find the “Certificates” section and click on “View Certificates”. In the Certificate Manager, navigate to the “Certificate Authorities” tab. Here, certificates are listed in alphabetical order. Select the specific certificate based on the website that is experiencing problems. Click the Edit Trust Relationship button at the bottom. In the Edit CA Certificate Trust Settings window, make sure that both the “This certificate can identify web sites” and “This certificate can identify email users” options are checked. Then click OK. Next, try accessing the site that was generating this error from the address bar of your browser. Check to see if the problem has been resolved. ### Disable Browser Proxy Settings Start the Firefox browser. Type about:preferences in the browser address bar to display the settings page. Go to the General tab. Type “Network” in the search box and look for “Network Settings”. In the search results, click on the “Settings…” button associated with “Network Settings. button associated with “Network Settings. Select the radio button next to “No Proxy” in the Connection Settings window. Click OK. Close any open tabs. Restart Firefox to see if the error has been resolved. ## What causes the SEC_ERROR_BAD_SIGNATURE Error Code in Mozilla Firefox? The aforementioned error message doesn’t appear on dubious websites, but it can prevent you from accessing legitimate websites like Facebook and others. The following factors could be to blame for this problem: **Third-Party Antivirus Software:** The third-party antivirus programme on your system will be the problem’s most frequent root cause. Such software frequently enforces restrictions on your web connectivity, preventing you from visiting certain websites. **Mozilla Firefox Extensions:** The extensions you added could also lead to a number of issues. You might be seeing the mentioned error message as a result of one of them tampering with certificates. Launching Firefox in Safe Mode will fix this. **Firefox Network Settings:** Your Firefox Network settings may also be the source of the error message. It’s possible that the problem is being brought up because you are using a proxy. ## Final Words When it comes to web browsers, only Firefox and Google Chrome are true rivals. The Mozilla Corporation created Mozilla Firefox, an open-source web browser that was first made available in 2002. The browser keeps getting better thanks to the regular updates it receives, becoming much faster and more stable while also receiving security upgrades. However, using Mozilla Firefox may present some problems for you. Firefox’s Secure Connection Failed (SEC ERROR BAD SIGNATURE) error prevents you from visiting websites that are straightforward to access using other browsers. We hope our article on “How to Fix SEC_ERROR_BAD_SIGNATURE in Firefox” will surely help you to do so. You can also go to the [official Firefox website](https://www.mozilla.org/en-US/firefox/new/) to learn more about this error. --- *End of Article*