How to Fix the Untrusted Connection Issue in Mozilla Firefox

Step 1: Adjust Date and Time Settings

Inaccurate date and time settings on your device can trigger this error. Follow these steps to correct them:

Step 1: Press Win + I to open Settings.

Step 2: Click on “ Time & Language ”.

Step 3: Select the “ Date & Time ” option.

Step 4: Turn off “ Set time automatically ” to manually adjust settings.

Step 5: Click “ Change ” under “Set the date and time manually” to input the correct information.

Step 6: Adjust your time zone from the dropdown menu and save changes.

Step 7: Restart Firefox to apply the updated settings.

Pro Tip: Ensure your time zone reflects your current location accurately.

Step 2: Delete the Cert9 File

Corrupted certificate files can also cause untrusted connection errors. Here’s how to delete the Cert9 file:

Step 1: Click on the menu icon in Firefox.

Step 2: Navigate to “ Help ” and select “ More troubleshooting information… ”.

Step 3: In the Application Basics section, locate the “Profile Folder” and click “ Open Folder ”.

Step 4: Close Firefox completely to ensure safe deletion.

Step 5: Find the “ cert9 ” file and delete it.

Pro Tip: Consider backing up your profile folder before making changes.

Step 3: Disable Any Proxy Services

Proxies or VPNs can interfere with your connection. Here’s how to disable them:

Step 1: Type about:preferences in the address bar and hit Enter.

Step 2: In the “General” section, locate “Network settings”.

Step 3: Select “No proxy” and save the changes.

Pro Tip: Ensure no unwanted add-ons are running that could act as a proxy.

Step 4: Turn Off Ad-Blockers

Ad-blocking extensions may block access to certain sites. Disable them following these steps:

Step 1: Click the extension icon next to the address bar.

Step 2: Navigate to “ Manage extensions ”.

Step 3: Disable any active ad-blockers from the extensions menu.

Pro Tip: If disabling fixes the issue, consider removing the extension altogether.

Step 5: Modify Certificate Settings

Tweaking certificate settings can help bypass the error:

Step 1: Click the menu icon in Firefox and go to “ Settings ”.

Step 2: In “Privacy & Security”, find the “Certificates” section.

Step 3: Uncheck “Query OCSP responder servers to confirm the current validity” and disable HTTPS-Only Mode.

Pro Tip: Changing these settings may affect your browsing security; proceed with caution.

Step 6: Clear Firefox Cache

Clearing cache can resolve loading issues:

Step 1: Open “Settings” from the menu.

Step 2: Navigate to “Privacy & Security”.

Step 3: Under “Cookies and Site Data”, click “Clear Data…”.

Step 4: Ensure both “Cookies and Site Data” and “Cached Web Content” are checked, then click “ Clear ”.

Pro Tip: Clearing cache may log you out of some websites.

Step 7: Update Firefox

Ensure that you are using the latest version of Firefox:

Step 1: Open “Settings” and go to the “General” tab.

Step 2: Click “Check for updates” in the Firefox Updates section.

Pro Tip: Regular updates enhance security and performance.

Step 8: Avoid Unsecured Websites

Accessing websites without valid SSL certificates can lead to errors:

Be cautious of sites that only utilize HTTP protocols. Ensure secure connections (look for the lock icon) before browsing.

Pro Tip: Always prioritize using HTTPS for secure browsing experiences.

What does the ‘This Connection is Untrusted’ error mean?

How do I avoid this error in the future?