Firefox Community Forum

I wish to add an exception to an address which I host locally. I've explored many options which didn't work such as: Adding HTTPS-Only Exception Disabling certain security features

As the title says, with both with https and http firefox displays this warning:

https://i.imgur.com/MQLsaCk.png

But no way to bypass it, trying to login to my ubiquiti edgerouter at http://192.168.1.1 or https://192.168.1.1

What can i do?

www.sejda.com,Your Computer Clock is Wrong Your computer thinks it is Jul 11, 2026, which prevents Firefox from connecting

After updating Firefox to a newer version, some websites that previously worked on the older version started displaying **"Page Not Secure"** and **"Page Expired"** errors, preventing them from loading correctly.

Hello, I am facing a very strange and frustrating issue with my website https://biografieblick.de/, and it is only happening on the firefox browser other browsers like chrome, edge or safari are loading the site perfectly fine. The Issue is it occurs occasionally, Yeahh IDK why. When I try to visit my site, Firefox gets stuck on a screen that says "Checking if the site connection is secure" and it looks like an loop sometimes.

This looks exactly like a cloudflare turnstile loop but I am NOT using cloudflare. I have double checked my DNS records and explicitly confirmed this with my web hosting provider. This block only triggers when using firefox.

12 hours ago Firefox stopped working .No reason ; no changes just the following message including access to this site.So now I have to access with edge . 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.

The browser prohibits access to the social network https://vk.com/ . The browser leaves a response: "Firefox has discovered a potentially significant security issue id.vk.com . Someone impersonating the site may try to steal data such as bank card details, passwords, or email addresses".

Сайт авторизации вконтакте не загружается по причине просроченной сертификации. Мобильная браузерная версия продолжает стабильно работать и открываться, позволяя зайти на сайт. Установка сертификатов МинЦифры не помогла.

Сертификат сайта

Hello, I run a movie and drama-related website: https://tvmon.com.co/. Recently, I’ve noticed that Firefox occasionally throws the following error when trying to access the site:

"Secure Connection Failed An error occurred during a connection to tvmon.com.co. . The OCSP response contains an invalid signing certificate. Error code: SEC_ERROR_OCSP_INVALID_SIGNING_CERT"

This issue is very strange because:

1. The site loads fine in Chrome, Edge, and Safari.

1. My SSL/TLS certificate is valid, up-to-date, and passes external tests (SSL Labs, etc.).

1. The error only appears occasionally in Firefox, refreshing sometimes fixes it, sometimes not.

1. Hosting and server logs show no issues at all.

I suspect this is related to Firefox’s stricter OCSP validation, but I’m not sure how to debug or resolve it. Since my site streams drama and movie content, this error is frustrating for users who rely on Firefox.

Has anyone else experienced this intermittent OCSP signing certificate error? Is there a known fix or workaround for Firefox-specific validation issues?

I have been having issues where I am unable to access the website: www.loki.ch. This is the web site for a Swiss railway magazine. I have always been able to access it previously, but haven't used it now for a few months. However this week when I've tried, I'm blocked access to it (see the attached screen shots). I do note that since I had previously access the web site, there have been updates to Firefox. However, when trying to use either Edge or Google Chrome, they also block me, but just say that unable to access the web site, nothing mentioned about being "Not Secure" as Firefox does. It's not a web site where you have to log in and/or use passwords. Contacting the magazine by Facebook messenger yields no response from them. Posting the issue on a Facebook group, other users have responded that they can access it (one was from Slovenia and the other in the UK). One mentioned issues from Australia where I am. It's not a dangerous or suspect web site, simply a magazine about Swiss Model Trains. I have tried adjusting settings to exempt it in Settings - no change. Not a anti virus issue. None of the suggestions in the FAQ have exactly the same scenario in the screen shots attached.

Surely there has to be some way to bypass whatever is in Firefox Security preventing me from accessing this web site?

성인사이트가 크롬과 엣지에서는 정상적으로 열리는데 파이어폭스에선 보안 연결 실패라고 뜹니다. 원래 파이어폭스에선 성인사이트를 차단하고 있는 건가요? 아니면 차단을 해제할 수 있는 방법이 있는 건지요 Adult sites open normally on Chrome and Edge, but on Firefox it says security connection failure. Is Firefox originally blocking adult sites? Or is there a way to unblock it

I am getting a message that secure connection failed, it is happening for Amazon.com and maybe netflix as I can't log on or access the sites

I'm reposting a question already opened here because a moderator suggested to do so. Actually I though I was posting to the international forum from the URL...

I was trying to access a local HTTPS website of an embedded device (a Siemens S7-1500 PLC) that is using a self-signed certificate, but was unable to go on (attached image #1, in Italian language) due to the the SEC_ERROR_REUSED_ISSUER_AND_SERIAL error. I've browsed a similar PLC webserver in the past, so the fact that the device exposes a similar certificate serial number is not so strange for me, considering also it's self-signed.

The problem is that I cannot follow the instructions of the Mozilla knowledgebase here because I'm not able to identify the correct certificate of the website!

In the attached image #2 you can see that the connection is detected as not encrypted, I suppose because only the form part of the HTML that is posting the data using HTTPS while the rest is using HTTP, but I'm not sure. If I click on the padlock icon (attached image #3) the info about the current certificate is not displayed.

Then I went into Tools > Options and searched for "certificates"; as you can see in the attached images #4 and #5, neither in the Servers tab nor in the Authorities tab I can find any item that is related to 192.168.10.2 (the webserver IP address) or Siemens (the embedded device manufacturer). But unfortunately the error persist! Initially there was a 192.168.10.2:443 line in the Servers tab and I removed it and restarted Firefox, but it didn't solve, so at the moment the situation is the one depicted by the attachments.

I had to use Microsoft Edge to access the website, but I would like to solve this issue and use Firefox instead. Is there anything else I can do to bypass the error? Why doesn't the error page provide a way to correctly identify the wrong certificate using its fingerprint and/or name? Or, maybe, is there a way to disable this check for local IP addresses or for items in a whitelist?

Thanks for your help.

Using firefox 140.6.0esr on Windows 10 with noScript and uBlock Origin

Infrastructure for my health insurance provider website uses a self-signed certificate. The infra has a different URL from the main page and was initially failing with "CORS failed", which turned out to be the cert issue.

I copied the infra URL from the dev tools network log and opened it directly, and accepted the invalid cert. I can see the new exception in cert_override.txt.

Then, after unblocking the site in uBlock origin, POST and GET requests to the infra URL succeed, but OPTIONS requests are still failing with "CORS failed", and security status "SEC_ERROR_UNKNOWN_ISSUER"

Is there anything else I can do so the OPTIONS request honors the exception in cert_override.txt?

Secure Connection Failed

An error occurred during a connection to upl-upm.pushbuttonformula.com. SSL received a record that exceeded the maximum permissible length.

Error code: SSL_ERROR_RX_RECORD_TOO_LONG

I am trying to access static IP addresses on my Intranet. I could in the past type in the IP address and I would get a notice that the site is not secure and allow me to continue to the site. Now it tells me that the website cannot be reached. I need to get to the GUI interface of cameras on my network. How do I get this to work?

When I try to access the Newsmax website, I get a black screen with the message which says,

"Secure Connection Failed The connection to www.newsmax.com was interrupted while the page was loading.

   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." 

I have no problem accessing other sites, so what can I do to get the resolved?

An error occurred during a connection to in.pinterest.com. 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 web site owners to inform them of this problem.