Can you attach a screenshot?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

• Use a compressed image type like PNG or JPG to save the screenshot
• Make sure that you do not exceed the maximum size of 1 MB

If you can't inspect the certificate via "I Understand the Risks" then try this:

Open the "Add Security Exception" window by pasting this chrome URL in the Firefox location/address bar and check the certificate:

• chrome://pippki/content/exceptionDialog.xul

In the location field of this window type or paste the URL of the website.

• retrieve the certificate via the "Get certificate" button
• click the "View..." button to inspect the certificate in the Certificate Viewer

You can inspect details like the issuer and the certificate chain in the Details tab of the Certificate Viewer. Check who is the issuer of the certificate. If necessary then you can attach a screenshot that shows the certificate viewer.

cor-el already listed the steps for further investigation if there isn't an obvious explanation, but I will add this:

When you get "untrusted connection" or certificate errors for pretty much all secure sites, the problem usually is one of the following:

(1) Error in your system's date, time, or time zone, which throws off certificate validity checks. Sometimes allowing computers to use an internet-based time source can introduce this problem.

(2) Firefox not being set up to work with your security software that intercepts and filters secure connections. Products with this feature include Avast, BitDefender, ESET, and Kaspersky; AVG has a Search Shield feature which can cause this error on search sites.

(3) On Windows 10, Firefox not being set up to work with the parental control software Microsoft Family Safety.

(4) Malware on your system intercepting secure connections.

So... which is it? Because you should not need to add exceptions for well run sites, period.

If you have any of those specific security products, that would be the first thing to check. We might be able to assist with specific next steps based on what you have if you tell us.

I disabled Avast. No change. IE works no prob. for all sites. There is a picture of what appears to be a policeman with a hat, his arm out, with a book by his hand. My time appears to be correct. (Where can I link to to ensure it is?) I don't use parental controls. (No kids). I had windows 7 but just upgraded to windows 10. Problem same with both OS. There should be a menu driven fix or change, that allows access no matter what. Some of the alerts, do not give that option. They give an option for get me out of here only, and a technical details link. Then you just can't go. Why can't I just turn https off at the menu? I should have full control over my own computer. It seems Firefox wants to dictate control to me. That is something I would like an answer to. I apologize for being upset, but this is the kind of thing Microsoft does, and is why I use Firefox as my default browser. I am sending this through IE, in order to ensure it gets there. I tried uninstalling Firefox and reinstalling it. No change. I ran Housecall. No viruses. On the verge of permanently uninstalling Firefox. That's a shame because it has some things I like. Need a real answer or a fix. (Preferably a fix)

I'm sorry for the inconvenience, but in order to get a better understanding of why Firefox believes the sites' certificates to be invalid, we need you to check another thing. You can use my test page to get the "full" error page:

https://jeffersonscher.com/res/jstest.php

Expand the "I understand the risks" section and look for an Add Exception button.

Note: You don't need to complete the process of adding an exception -- I suggest not adding one until we know this isn't a malware issue -- but you can use the dialog to view the information that makes Firefox suspicious.

Click Add Exception, and the certificate exception dialog should open.

Click the View button. If View is not enabled, try the Get Certificate button first.

This should pop up the Certificate Viewer. Look at the "Issued by" section, and on the Details tab, the Certificate Hierarchy. What do you see there? I have attached a screen shot for comparison.