Firefox Community Forum

Have used Firefox for years. Today, went to standard sites (eg weather info, local blog site) and get told they aren't secure and can't be loaded. Have tried re-installing Firefox, clearing cookies but no change. No problem with same sites from Chrome. Message is:

Looks like there’s a problem with this site

www.portlandbirdobs.com sent back an empty page. What can you do about it?

   The site could be temporarily unavailable or too busy. Try again in a few moments.
   If you are unable to load any pages, check your computer’s network connection.
   If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web.

Error Code: NS_ERROR_NET_EMPTY_RESPONS

To be honest. Firefox is starting to be a big pain to use. I'm starting to see more and more of this screen where it say's "Be careful. Something doesn't look right" Even when i go to the advance and say proceed. Nothing happens and i'm getting no where. I know many of the sites don't have anything to do with asking for credit card, Scam or even having popup's. I test the sites in other browsers and there work without any issues. But Firefox is starting to lock me out of many sites due to this. How can i make this stop. As i used Firefox for many years.

The sample that is in the screenshot is a Anime data base that i have also used for years. But today shows this. But was working fine yesteday. What is going on and how can i fix it. So i can start using the browser that i love on the sites i want to.

Please help me purchase a NM Gift Certificate for my daughter Caroline Campbell. She has an account with you but I do not and I'm overwhelmed by the process. Lisa Nichol [edited email from community support forum]

I just installed Firefox on my PC haven't had it on this computer since reinstalling windows - I imported my bookmarks and passwords from Edge, thinking it would be a seamless transition, since I used Firefox in the past without much trouble.

Two weeks on, about 95% of every page I open gives an error similar to the one below, and I have to shift+refresh several times to get it to reload before it goes away, (some sites still don't open).

I wonder how common this issue is, and how people fixed it?

Be careful. Something doesn't look right.

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

Go back (Recommended)

Hide advanced

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 connect.mozilla.org. The certificate is only valid for: *. eero.com. What can you do about it? Probably nothing, since it's likely there's a problem with the site itself. Sites use certificates issued by a certificate authority to prove they're really who they say they are. But if you're on a corporate network, your support team may have more info. If you're using antivirus software, try searching for potential conflicts or known issues. View the site's certificate Learn more about secure connection failures Error Code: SSL_ERROR_BAD_CERT_DOMAIN Jun 5, 2026 10:58:34 AM GMT+10

Proceed to connect.mozilla.org (Risky)

Did Not Connect: Potential Security Issue

Firefox detected a potential security threat and did not continue to nrega.nic.in because this website requires a secure connection.

What can you do about it?

nrega.nic.in 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.

Probably nothing, since it’s likely there’s a problem with the site itself.

Hello,

The website I log in for internet banking (https://www.sparkasse-rhein-maas.de/de/home.html) is shown as written in brackets when opened in Edge, but as www.sparkasse-rhein-maas.de/de/home.html when I open it in firefor. And Firefox tells me it's not safe when I want to log in. BUT - as I've only just discovered when I copied and pasted it in here - when copied it shows as https://www.sparkasse-rhein-maas.de/de/home.html, so safe after all? How can that be? I hope there's a good explanation.

Thanks in advance Bettina

Moderator note: This question has been edited to correct the formatting.

When I bring up the certificate-expired URL

<https://oaklandwiki.org/>

in Firefox 149.0 on Windows 11 I am told "You have added a security exception for this site." But not how to remove it. How do I do that? I did not see anything in Settings or about:config; did I miss it?

Hello,

Since this morning, I haven't been able to access Bsky on my laptop because of a supposed HSTS risk, which means I can't add an exception to visit it. I use Firefox on my Android and going to the mobile version of the website lets me in no problem, so I assume there's an issue with my laptop.

I'd usually wait a few days and let it solve itself but just in case it's something on my end, I'd like to solve it! I'm on 151.0.4 (64-bit), don't use a VPN or an anti-virus, I have a couple of privacy add-ons but they've been here forever and they've never caused a fuss. I can post a screenshot of the error code and the certificate it sends me if it's any help.

I'd appreciate any pointers! Thanks!

The SSL cert has been installed by the entity (Gridhost) from whom I have bought it for 20 years. And as explained, Firefox still shows it as Not Secure while Chrome say it is secure.

Zachowaj ostrożność. Coś tu nie gra.

Firefox wykrył potencjalnie poważny problem bezpieczeństwa na witrynie ohttp-gateway-merino.services.mozilla.com. Ktoś podszywający się pod nią może próbować ukraść dane karty płatniczej, hasła, adresy e-mail lub coś innego.

Witryna „ohttp-gateway-merino.services.mozilla.com” określa poprzez HSTS (HTTP Strict Transport Security), że Firefox ma się z nią łączyć jedynie w sposób zabezpieczony. Dodanie wyjątku w celu odwiedzenia tej witryny jest niemożliwe.

I am writing to report a recurring technical issue that began appearing today across multiple devices.

When attempting to access Google websites (specifically Gmail and Google News) using the Firefox browser, users are being prompted to identify themselves via a security certificate. Previously, this authentication step did not occur, and access was seamless.

Key Observations:

Impact: We have confirmed this behavior on three firm-issued computers as well as one personal device.

Browser: The issue is isolated to Firefox; other browsers appear unaffected.

Timing: This behavior was not present yesterday; it started manifesting today.

We suspect this may be related to a recent network configuration change, a new security policy rollout, or a browser update that has altered how Firefox handles trusted connections to Google services.

Could you please inform me whether there have been any recent changes to our SSL inspection proxies, root certificate stores, or DNS configurations? Additionally, does anyone else on the team have visibility into a widespread incident affecting Google certificates, or should we proceed with troubleshooting individual profiles?

Subject: Urgent Assistance Needed with Certificate Installation

Dear Team,

I hope this message finds you well. I am in urgent need of assistance regarding a Linux-based system where we have the Firefox browser installed. I need to establish a secure connection with one of my servers, which requires the installation of a certificate.

However, I am unable to locate the certificate export button in the certificate view or anywhere else in the browser. I have tried several methods without success.

Could you please help me with this issue as soon as possible? Your guidance would be greatly appreciated.

Thank you very much!

Best regards, Kishor

When trying to access many popular websites with Firefox on my Fedora 43 installation, I am greeted with a security warning page with the SEC_ERROR_UNKNOWN_ISSUER error. For most of these websites I can simply accept and continue, but HSTS-only sites will not permit this.

Affected websites include but are not limited to (based on exceptions in the certificates section of Firefox settings):

• github.io (many subdomains)
• purdue.edu (many subdomains)
• iu.edu
• ebay.com
• cbsnews.com
• iwm.org.uk
• home.cern
• celestrak.org

Any help in resolving this is appreciated.

I'm using firefox in my company's intranet, it needn't to check whether the website is secure or not. So this warning is so annoying.

I want to turn it off, but how? The instructions I searched on the Internet are out of date.

The browser version is 137.0

Firefox is giving me an error on https://stemgateway.nasa.gov but the site is perfectly accessible using MS Edge and using Firefox on another computer. I uninstalled and reinstalled Firefox, changed the proxy settings to not use a proxy, tested a VPN, and changed DNS servers. Below is a picture of the error and of the certificate which seems to be present in Firefox already.

Secure Connection Failed

An error occurred during a connection to citizen.jhpolice.gov.in. PR_CONNECT_RESET_ERROR

Error code: PR_CONNECT_RESET_ERROR

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem.

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