Ways to fix SEC_ERROR_UNKNOWN_ISSUER error in Mozilla Firefox

Mozilla Firefox users, even if infrequently, they can still find various errors while browsing the web. As an example, when you navigate to a site of your choice, you may get a SEC_ERROR_UNKNOWN_ISSUER error code.

Error “This connection is not trusted” and other similar errors accompanied by the code SEC_ERROR_UNKNOWN_ISSUERindicates that the browser has detected a certificate discrepancy when switching to the secure HTTPS protocol, which is intended to protect the information transmitted by users.

Causes of error with SEC_ERROR_UNKNOWN_ISSUER code:

1. The site is effectively insecure since it lacks the necessary certifications to demonstrate its security;

2. The site has a certificate that gives some kind of guarantee on the security of user data, but the certificate is self-signed, which means that the browser cannot trust it;

3. On your computer, the file cert8.db in the profile folder of Mozilla Firefox, responsible for storing identifiers, it was damaged;

Four. The antivirus installed on your computer has SSL scanning enabled (network scan), what may be causing problems with Mozilla Firefox.

Alternatives to correct the error with the SEC_ERROR_UNKNOWN_ISSUER code

Method 1: disable SSL scanning

To check if your antivirus program is causing the error with the SEC_ERROR_UNKNOWN_ISSUER code in Mozilla Firefox, try suspending your antivirus program and check if the browser has problems.

If Firefox works fine after disabling antivirus, you need to look in your antivirus settings and disable SSL scanning (network scan).

Method 2: restore the cert8.db file

Then, we must take care that the cert8.db file has been corrupted. To fix the problem, we must eliminate it, after which the browser will automatically create a new functional version of the cert8.db file.

First, we will have to enter the profile folder. To do this, click the menu button in your web browser and select the icon with a question mark.

In the secondary menu that appears, click on “Información para la resolutionThe "resolution" refers to the ability to make firm decisions and meet set goals. In personal and professional contexts, It involves defining clear goals and developing an action plan to achieve them. Resolution is critical to personal growth and success in various areas of life, as it allows you to overcome obstacles and keep your focus on what really matters.... of problems”..

A window will appear on the screen and you will be asked to select the “Show folder”..

The profile folder will be displayed, but before working with her, close Mozilla Firefox completely.

Go back to the profile folder. Find cert8.db in the file listing, click on it and go to “Remove”..

Run Mozilla Firefox and check the error.

Method 3: add page to exception

If the error with the SEC_ERROR_UNKNOWN_ISSUER code is still not resolved, you can try adding current site to firefox exceptions.

To do this, Press the button “I understand the risk”.and when it shows, select option “Add exception”..

In the window that appears, Press the button. “Confirm the security exception”.and the site will open without interruption.

We hope these tips have helped you fix the SEC_ERROR_UNKNOWN_ISSUER error in Mozilla Firefox.

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