Lots of people report this every week, so you are not alone! Let's see whether we can help you track it down.

When you get this 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?

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.

Alternately, you can examine the certificate to which Firefox is objecting to see whether the issuer information points to the culprit. Take my test page for example:

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

You should see an "I understand the risk" heading in the page. If you expand that section, you should find an Add Exception button. 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, then View. If View is not enabled, try the Get Certificate button first. Then in the Certificate Viewer, look at the "Issued by" section. What do you find there, and/or under Certificate Hierarchy? I have attached a screen shot for comparison.

Thanks for the quick, detailed response!

1) date/time/zone correct and not set to internet time.

2)I use Kaspersky and when this really became an issue I found forum (and others) suggesting this as a possibility, so I disabled it entirely. Still had issue. Rebooted PC with K disabled, still had issue.

3)I'm using Windows 7 and am allowing others to finish beta-testing 10 though I'll doubtless upgrade during Microsoft's 'window'.

4) A possibility, I'm sure, even though such isn't being detected. This would be something I'd like to explore. I say this because I'm also having problems with IE 11. Not the same issue, but there are certain sites (Amazon, and other non-https sites) that the browser will simply not load. It'll bring up Google and conduct a search, but will not take me to any of the links Google suggests).

BTW, tried to go to your test site in FF and got the Untrusted message. I do have data that comes up when I view the attempt to make the exception, and can provide that it if helps.

Thanks again for the response, and I'll take any suggestion re: checking for malware. Something lodged in "host" maybe? Not that if you replied 'yes' I'd know what do to about it...

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.

aitchem said

BTW, tried to go to your test site in FF and got the Untrusted message. I do have data that comes up when I view the attempt to make the exception, and can provide that it if helps.

Yes! That is what I'm asking for, what is under "Issued by" and the "Certificate Hierarchy" that could point to an interloper instead of Comodo.

Ok, Issued By:

CN - Easy Tech O - Easy Tech OU - not part of certificate

Valid today-7/25/16

When I search that certificate issuer, it is associated with: "Easy-Hide-IP VPN". Does that sound like a product or service you use?

The problem is that inserting itself as a "man in the middle" of your connections means this company's software/service can read everything you do on the web. I'm not sure I would trust them (or their security infrastructure) to that extent.

Are you using Easy Hide VPN?

• http://superuser.com/questions/582739/certificates-issued-to-x-not-signed-by-correct-authority

Wow, it was that simple a thing?? I tried Easy Hide months ago and just stopped using it. Never did uninstall it till moments ago, and now I can access https sites without a hitch (including yours, Jefferson). Just goes to illustrate the potentially far-reaching effects of trying out a new program.

Now I have new issues, of course - after the uninstall and reboot. One is system message "Could not load file or assembly 'MOM.Implementation' or one of its dependencies. The system cannot fine the file specified." Not sure what that affects but it seems once I 'okay' that message all is operating normally.

The other is a FF issue - when it launches, I'm using an old profile. All of the add-ons have a 'use at own risk' message attached to them, probably because they're not (or are barely) compatible with the version of FF I'm now running years later. But at least now I can get to Mozilla support pages to figure out how to change profiles.

Thanks to everyone for all the time you took to help!

The profile switch came from when I tried a refresh of FF as a solution to the Untrusted Site issue before the Easy Hide uninstall, btw, not as a result of the uninstall.

And switching profiles was easy too.

Thanks again for the help!

My problem is not the same as this one. I enter the URL and get NOTHING. When I use opera I get the untrusted stuff like that mentioned above.

It looks like FF does read from the site but doesn't display a thing.

Hi grgoffe, since your problem is different, I suggest starting a new question.

You can do that at the following link. Scroll down past the suggestions to continue submitting your question: https://support.mozilla.org/questions/new/desktop/fix-problems