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Firefox Nightly updated and now I can't access my banking or financial websites? What can I do to resolve this?

  • 2 replies
  • 1 has this problem
  • Last reply by cor-el

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I am using Windows 10 Pro 64 bit and using Firefox Nightly. Nightly performed a couple of updates today, 2-22-18, and now I am unable to access my banking or financial online websites. I receive a "your connection is not secure" error. Yesterday, 2-21-18, I was able to navigate to all my banking and financial websites without any problem. Currently, I am not even able to get to a login screen to the websites. I can however, navigate to all the websites using Microsoft Edge. However, I do not like using Microsoft Edge as my web browser and much prefer Firefox Nightly.

I would like to have some help resolving this issue with Firefox Nightly.

Thank you very much,

Terry Small

Here is an image of the error that I am receiving:

Your connection is not secure

The owner of has configured their website improperly. To protect your information from being stolen, Nightly has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Nightly may only connect to it securely. As a result, it is not possible to add an exception for this certificate.

Learn more…

Report errors like this to help Mozilla identify and block malicious sites

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There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

  • uses an invalid security certificate SSL_ERROR_BAD_CERT_DOMAIN
  • configured their website improperly

How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites

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Hmm. I see the same if I use the current Nightly build. The certificate chain looks OK when I check this in the Servers tab, so I don't know what gets wrong here. It could be an issue with the signature or something else. Things like this can always happen if you use an unstable Nightly build.

Try the mozillaZine Builds forum to see if this is a known issue.