Firefox Community Forum

At your recommendation I signed up to Ad Avoid and now FireFox tells me that I could/should not access BT.Com because of the certificate issued by Ad Avoid

Hi, Since three or four months, whenever I log into Outlook live, either on Mac or Windows PC, I get a security warning saying that the information will not be secure (Please see attachment.) When I log into the same account, from Edge for example, I do not get the warning popup. I really enjoy using Firefox and would love to continue but this case is worrying me a bit. Any idea to help? Thank you very much, Mathieu B.

My anti-virus reports that 30 to 100 times per day, it blocks firefox.exe attempts to establish a connection relying on an expired certificate to to www.temu.com. Can you please stop your attempts ? Or tell me how to stop them ?

My laser printer will not print due to low toner. However, when I click on "more information" to find out the toner level, that site is shown as unsecure and cannot be accessed.

Give me back my access to irccloud.com. I have been using that website for over 5 years on FireFox and then this morning you denied me access. Thanks for checking and correcting.

Whenever I try to open Github specifically I get:

Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for github.com. The certificate is only valid for the following names: cloudflare-dns.com, *.cloudflare-dns.com, one.one.one.one

Error code: SSL_ERROR_BAD_CERT_DOMAIN

I spent time looking into this, used a new IP address and tried updating the certificate for github, however I'm not particularly skilled when it comes to this, so any assistance would be much appreciated.

Firefox detected a potential security threat and did not continue to apps.ngte-welfaretrust.gov.bd because this website requires a secure connection.

What can you do about it?

apps.ngte-welfaretrust.gov.bd 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.

The issue is most likely with the website, and there is nothing you can do to resolve it.

If you are on a corporate network or using antivirus software, you can reach out to the support teams for assistance. You can also notify the website’s administrator about the problem.

please provide directions for fixing the navigating inside NEwsmax site

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.

If I try to log into my router at 192.168.1.1 I get a message that says "Warning: Potential Security Risk Ahead". I expect that, but when I click on the Advanced button it doesn't do anything. Works fine with Chrome, so not my router or anti-virus. ???

Windows 10 Firefox 148.0

i'm not connecting to my web site www.kroger.com something has me blocked . i tried everything to get in the message says secured connection failed . i called kroger stores and they said it is an internet problem .

Bitdefender security software Online Threat Prevention "Notifications" are blowing up stating the following: "firefox.exe attempted to establish a connection relying on an untrusted certificate to incoming.telemetry.mozilla.org"

The issue began approximately 17:00 UTC November 16, 2025

Please investigate & update the certificate or we may need to move to a different browser.

Screenshot submitted.

D.

I am trying to access certain HTTPS website and some of them show PR_CONNECT_RESET_ERROR in Firefox. This error is not present in Edge or Chrome. Any ideas on what could be the problem?

An error occurred during a connection to delta-executorr.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 website owners to inform them of this problem.

Here's what I've tried (none of these works):

   DNS over HTTPS turned off
   Uninstall all add-ons
   Reinstall Firefox
   Create new profile and set it as default
   Delete/rename certs.db in the Firefox profiles folder. 

I'm tired fixing errors which become more complex and solutions are written for people who have the time an knowledge to waste fixing these constant issues in FIREFOX, Time to change browser.

I don't know if this is relevant but one of the website that does not work is https://delta-executorr.com/

I used to be able to connect with Firefox (with a warning message from you) to my local Netgear NAS, but now it just says:

Secure Connection Failed An error occurred during a connection to 192.168.1.100. Peer using unsupported version of security protocol. Error code: SSL_ERROR_UNSUPPORTED_VERSION 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. This web site might not support the TLS 1.2 protocol, which is the minimum version supported by Firefox.

How can I still override this with Firefox. It's really important I can connect to my NAS.

With thanks,

Nick Curley

Today when I try to access my Yahoo mail from www.yahoo.com, encountered Potential Security risk. Is this a problem encountered by others as well ? I still looking on how to report the issue to FireFox.

got a new computer. Geek Squad added my firefox, but it now won't allow my worlplace (Lowes) for schedules and pay.

Secure Connection Failed

An error occurred during a connection to lius.myloweslife.com. Peer reports it experienced an internal error.

Error code: SSL_ERROR_INTERNAL_ERROR_ALERT

I get the "Secure Connection Failed" when trying to go to a web site.

I know the web site is fine. You have stopped offering the "Go anyway" button!

https://thebougainvillahouse.org/

... it's a 503 charity we give money to.

Fred

Firefox blocked your visit to this site because the certificate provided for agents.shohoz.com has been revoked and isn’t trusted anymore.

Error code: SEC_ERROR_REVOKED_CERTIFICATE

View Certificate

My university website (brightspace) is blocked by "Warning: Potential Security Risk Ahead" and clicking advance does not allow me to continue. I was using brightspace when it suddenly became blocked and I have received errors stating it was an HSTS error to now an expired certificate. I have tried to restart Firefox and clearing the website from my history and clearing cache, but nothing worked so far. Accessing this website has only been an issue on my Firefox on my laptop. The website's servers is not having issues, my other devices can access it flawlessly, and using other web browsers on my laptop does not cause any issues. I would like not to switch my browser, so any help to accessing this website would be greatly appreciated