Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

Check out why the site is untrusted (click "Technical Details to expand that section) and if this is caused by a missing intermediate certificate then see if you can install this intermediate certificate from another source.

You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates.

• Click the link at the bottom of the error page: "I Understand the Risks"

Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate".

• Click the "View..." button and inspect the certificate and check who is the issuer of the certificate.

You can see more Details like intermediate certificates that are used in the Details pane.

If "I Understand the Risks" is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".

Note that some firewalls monitor secure (https) connections and send their own certificate instead of the website's certificate.

The top solution seemed to work for a few searches. However, it started right back. (could have been a hiccup too).

Second solution under technical details says: www.google.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is not trusted. (Error code: sec_error_untrusted_issuer)

I also manually hit get certificate and it still does it.

Hi

Your firewall is configured to 'ALWAYS SCAN ENCRYPTED CONNECTION'

Chose option 'Scan encrypted connections if Parental Control is enabled' to solve the problem.

Regards.

I am running latest Firefox update (v23) and Kapersky Pure 3.0 on an old Windows XP box that is about to be retired.

I had the same Untrusted Connection error and even abandoned Firefox and used Chrome for awhile. After further investigation, it looks like the error is rooted in my firewall/security software inserting its own Issuer certificate

After receiving Untrusted Connection error, check the Technical Details. My error had to do with the issuer certificate not being trusted. Try to bypass the execption and view the certificate it wants to load. The issuer on the error I was getting was always Kapersky.

Searching Mozilla Support some more yielded the chosen solution from philipp to this post...

... which directs to this Kapersky help page

If Kapersky is your internet security solution

1. Find your way to settings->advanced settings -> network.
2. Check the option to scan encrypted connections.
3. Install the certificate Kapersky provides. (I found that Kapersky could install to Chrome and IE, but failed to install the certificate to Firefox.)
4. I followed the instructions that were then provided to install the certificate by hand.

I no longer have Untrusted Connection error problems using Firefox on this box.

I hope there are enough breadcrumbs on the thread to help you. Good luck.