Firefox Community Forum

Firefox automatically updated on my old Mac (OS 10.15.7). Since then every website I try to access gives a "Security connection failed" - Amazon, Google, even Firefox support. What the heck has happened. This browser is useless now.

ATT is my internet service provider. I use their website as my home screen. Yesterday, I started getting an error message when I tried to go on-line. I have contacted ATT, and they have determined that the problem is with Firefox, and not their website. I can go from the ATT screen to any other website, and it works fine. This is the message that I get:

Secure Connection Failed

An error occurred during a connection to www.att.com. You are attempting to import a cert with the same issuer/serial as an existing cert, but that is not the same cert.

Error code: SEC_ERROR_REUSED_ISSUER_AND_SERIAL

   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.

This is the 4th time I've reported this problem. Here's the warning I get every day only after I have already been loading Newsmax pages with no problems:

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.

Learn more…

There are no other sites in which I have this problem with FF x64 DE. In Edge, I see the newsmax pages load while the FF x64 DE https//newsmax.com xontinues to genberate the above message and fails to load the screen.

Please fix.

Thanks, WaltC

''''Was connected with Montana Dinner menu Charlottetown, PEI and the following popped up???? '''' Secure Connection Failed

The connection to www.montanas.ca 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.

What should I do, this has never happened before??????

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.

I noticed Firefox sometimes gives extra warnings when using payment gateways on healthcare service websites. Is Firefox stricter with SSL certificates than other browsers? For instance, visit here visit here

and test the checkout security prompts.

when I try to open a particular website, firefox keeps blocking it and says its an error. I cannot open this website. how do i get passed this.

Secure Connection Failed

An error occurred during a connection to www.cowdenbeathrotary.org. Peer reports it experienced an internal error.

Error code: SSL_ERROR_INTERNAL_ERROR_ALERT

   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.

Learn more…

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

Hi, I can't connect to my NAS anymore, via private IP. Impossible to add an exception for my auto-signed certificate. Immediate solution : stop using Mozilla. Another one ?

Thanks

Reviewing posts pertaining to SECURE CONNECTION FAILED and error code related to that message, one of the suggestions found on-line is to delete any listing from the Certificate Manager that is/may be a problem. However, NONE of those suggestions or discussions makes any mention about "how does one determine which listings those are?"

Relative novice here; was considering whether the "solution" was to merely delete all of the certificate listings, with the hope that the system would then repopulate what was necessary as time went on; some on-line information seems to indicate that to be not a good course of action . . . so my course of action has been to do nothing.

Question remains: how does one determine which listings can be deleted?

Thanks for any clarification.

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.

Running Surfshark on Windows 10 or 11 and Unbuntu 24.04. Some sites and attachments giving error failures. Happening with Firefox and Edge. Need troubleshoot source.

"Secure Connection Failed

An error occurred during a connection to forkliftgrocery.com. PR_END_OF_FILE_ERROR

Error code: PR_END_OF_FILE_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."'

Attachment error.