Firefox Community Forum

I have started receiving a secure connection failed error message for a portal log-in website that worked fine for the past 6-7 months (see attached document). Other people in my group use Firefox and Bitdefender to access the portal and none of them are having this issue.

I originally believed the problem to be my anti-virus (Bitdefender) and worked with them to resolve the problems. After trying various solutions including clearing my cache, using private mode and turning off different components of their software, Bitdefender believes the problem is with my browser setting and not their software. I also tried accessing the portal using Chrome in both regular and incognito modes and cannot access the site which would seem to rule out the problem being a Firefox browser problem but contacting Firefox support seems to be the next logical step.

I have been to the Firefox FAQ and saw similar problems with potential solutions - DNS over HTTPS, TLSKEYLOGGING issues, add-on exceptions - none of which worked. I have the most recent version of Firefox and am running Windows 11 home version.

Sometimes if I hit refresh after receiving the error message, the browser will try to connect and I will get a server time out message. If I keep hitting "try again", sometimes the portal log-in screen will appear and allow me to log-in. The key word is "sometimes" since often I just keep getting the server time out message.

Any ideas for me to try from this forum?

There is seriously something wrong with the way Firefox operates. There is nothing wrong with the following site so why am I seeing this message?

Be careful. Something doesn’t look right.

Firefox spotted a potentially serious security issue with news.sky.com. Someone pretending to be the site could try to steal things like credit card info, passwords, or emails.

news.sky.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site. Advanced What makes the site look dangerous?

The site is set up to allow only secure connections, but there’s a problem with the site’s certificate. It’s possible that a bad actor is trying to impersonate the site. Sites use certificates issued by a certificate authority to prove they’re really who they say they are. Firefox doesn’t trust this site because its certificate isn’t valid for news.sky.com. The certificate is only valid for: . What can you do about it?

news.sky.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.

Over and over again when I try to open a website I get the notice that says "Secure Connection Failed". I have to restart my laptop and then I can open the website that I tried to access before. I've tried using the suggestions in the forum with no result in solving this problem. I've attached the page that comes up showing the problem.

My email is jamek2006@yahoo.co.uk but when I try to Log In I am told the site is insecure and the place for password is blocked.

Kindly assist.

Здравствуйте. Я живу в России и у многих Российских сайтов отозвали сертификаты безопасности, но нам гражданам этой страны приходится пользоваться данными сайтами на свой страх и риск. В последних версиях Firefox не даёт войти на данные сайты даже на свой страх и риск. Прошу Вас от лица всех людей проживающих на территории России вернуть кнопку "принять риск и войти на сайт".

Заранее спасибо.

https://accounts.firefox.com/?context=oauth_webchannel_v1&entrypoint=fxa_avatar_menu&action=email&service=sync&client_id=5882386c6d801776&response_type=code&access_type=offline&scope=https%3A%2F%2Fidentity.mozilla.com%2Fapps%2Foldsync+profile&state=lxOkn6sd6-N3G1OsYU2hEQ&code_challenge=weuFT-Sxy3dZMJ8o0LzdHVJ8lKgMcpzxQeTNUoXQy_s&code_challenge_method=S256&keys_jwk=eyJjcnYiOiJQLTI1NiIsImV4dCI6dHJ1ZSwia2V5X29wcyI6W10sImt0eSI6IkVDIiwieCI6ImI1NUdROTg3UlNzY2hWMTVmQ05qd3hTMkN6TE5VSWpBWHZOVzRBMmJLcjAiLCJ5IjoidC14ZDI0c2lPZF9tV3JWWXZTRWRBVFRaWC0zMi1yMWtDY3QycmgxQ3NGVSJ9

Your connection is being intercepted by a TLS proxy. Uninstall it if possible or configure your device to trust its root certificate.

HTTP Strict Transport Security: true HTTP Public Key Pinning: true

Certificate chain:

MIIDVzCCAj+gAwIBAgIJALTLOd8k2gk/MA0GCSqGSIb3DQEBDQUAMGAxCzAJBgNV BAYTAkNOMRAwDgYDVQQIDAdKaWFuZ1N1MRAwDgYDVQQHDAdOYW5KaW5nMQwwCgYD VQQKDANaVEUxHzAdBgkqhkiG9w0BCQEWEHhpYW9taW5nQHp0ZS5jb20wHhcNMTkx MTE1MDE1NzE3WhcNMzYwNDE5MDE1NzE3WjB2MQswCQYDVQQGEwJDTjEQMA4GA1UE CAwHSmlhbmdTdTEQMA4GA1UEBwwHTmFuSmluZzEMMAoGA1UECgwDWlRFMRQwEgYD VQQDDAsxOTIuMTY4LjEuMTEfMB0GCSqGSIb3DQEJARYQeGlhb21pbmdAenRlLmNv bTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAK7IgFTsi2z35wX9310R xB7AoY+E2nja2t4RhEyul5yZjbOjJ8AESy8xTvdKn/rQYZJuUgpH/tQiWRgTXFax afqoP+43a5j4+7W7Gvqf2rW7J/Y74E1L7dwJvImWdSXRAvLSSvD1L86mmoQ2kyj6 xdR+x5O1xOsRElH3breVgaYTiaxK8fPOVreUkNCBfrxP5Kd/jBDiFxKHaC1zRw9m P71CFjnu1jidbfMTF97tfosNNb0ZWGwXWG8yhjMkMx5knTzrN2ZYHziqLYtiWdAd T/sTP/kvxMZm9nXAC7F8t+IJblCG87PcVyQO6Pj+cknTxwipvTRnOf0rp3iPjVMB 2hcCAwEAATANBgkqhkiG9w0BAQ0FAAOCAQEAw92iPTa2P4ZRy1qjmgTDhS2V2BqW 288VT8Z7bBMpnYdY488iJNkI2H7AhDmaUR9YbzXb3ntf6E7fesZTSsdeDak18Cv/ uakWIEQOAs3RismlOCaQFwP/qyLj7+8l1zOeE2EIWgtYgEBgsML+utfPpaw9XXDk 0hsdLFwPduZGWRXs2gfEgSyW385zvEhYLQmwZTuBMBlhsGgKmNamYvsahr3kTqo3 mvwAxoTmiRQcue9YhX9BnMurt3XxC1oYRqK3TFgV6I+jXwVj9wL4L7In9MGp6InI TQ6YWlxGYZUtUD6BpPGgEyZogpvoX7t/qyHh19I5uZsxg4FKmiDpi4eLrQ==

Здравствуйте! Не могу перейти на официальный сайт поликлинике "http://18pol.city.kharkov.ua/" чтобы срочно записаться на прием к врачу. Браузер Firefox постоянно выдает ошибку " Будьте осторожны. Что-то выглядит не так.". Сайт безопасный и официальный, но браузер все ровно не дает возможность перейти.

‘Firefox is blocking me websits or torrent sites because the certificate is outdated I have no option to carry the risk an acces it!!!’ This is disgusting!! Many good websites habe no certificates. It is obviously used as censorship. What can I do? I used the Testa del Rutor terrent

After updating software and restarting my laptop (Lenovo running windows 10 or 11) Firefox now displays this message for every web page (this example from attempting to access Gmail, but same message with all other sites I have tried):

"Be careful. Something doesn’t look right.

Firefox spotted a potentially serious security issue with mail.google.com. Someone pretending to be the site could try to steal things like credit card info, passwords, or emails.

mail.google.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site."

I now can't access any pages using Firefox. Long term user, so I hope you can help me! C

Since I updated a week ago I keep getting a warning of a bad site on sites that I know and trust. The problem is www.ui-deref.com Any ideas how to correct this?

Secure Connection Failed

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. What can you do about it?

The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem.

Error Code: PR_CONNECT_RESET_ERROR

this is the entire error message.

Subject: Persistent “Secure Connection Failed” after SSL certificate was re-issued – cannot clear cached certificate Hello Firefox Support, I am experiencing a persistent SSL certificate problem that only occurs in Firefox. Background

Domain: j3tourshongkong.com (and www.j3tourshongkong.com) The domain was recently moved to a redirect service (redirect.pizza) A new valid SSL certificate was issued by Let’s Encrypt via the redirect service The certificate is confirmed working by the certificate issuer and by redirect.pizza support

Current situation

HTTPS works correctly in Chrome, Edge, Safari, and on mobile browsers HTTPS works correctly on the same computer when using Chrome In Firefox (both normal and Private windows) I continue to receive “Secure Connection Failed / Not Secure”

What I have already tried

Cleared cookies and site data for the domain Cleared all recent history (including cache) Tested in a Private Window Restarted Firefox multiple times

None of these steps resolved the issue in my current Firefox profile. It appears Firefox has cached the previous (invalid) certificate state and is not refreshing it, even though a valid certificate is now being presented by the server. Could you please advise:

Is there a more thorough way to force Firefox to discard a cached SSL certificate for a specific domain? Or is this a known issue that requires a fix on the Firefox side?

I am happy to provide any additional technical details or screenshots if needed. Thank you for your help. Best regards, Jamie Lloyd

brand new Dell Pro 14 Plus laptops (PB14250), Initial install of OS,(Win 11 Enterprise, v 26200 25H2). All updates from Dell and Microsoft. Laptop is domain joined, on a hardline network connection. Only other browser is Edge, and has no issues. Installed fresh install of Firefox x64 (v153.0) to machine. ALL SITES attempted return this error. Google, Amazon, even trying to get to the support.mozilla.org return this error. In lower left while trying, the messages relating to the TLS handshake being performed can be seen. Disabled Proxy, restarted and no change. Disabled enterprise root certificate, restarted and no change Uninstalled, power cycled Laptop, reinstalled, power cycled, no change Issue is not preset at all with Edge. User needs Firefox as a specific critical vendor only supports Firefox for their portal.

In this case I accessed my Acer account and clicked on my notebook. I then got the screen shown in the image. I could access the page with Opera, Chrome, and Edge.

This is happening a lot, and is rendering Firefox unusable as my default browser.

I'm trying to access livingshield.org? When I try to access this website, I keep receiving secured connection failed. I need to access this website to register for courses

All of a sudden almost every site I try to enter comes up with "Secure Connection Failed". This started happening on Friday, July 10th for the first time. I've read almost every article in the Firefox's community forums and tried multiple actions and nothing stops this. I don't know why this all of a sudden when it never did this before. I hope someone can tell me how to stop this from happening].