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

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

http://kb.mozillazine.org/Error_loading_websites

https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean

Often, "Secure Connection Failed" means "Connection Failed (trying to load a secure page)". In other words, not a security problem, just a connection problem.

Many thanks for this response. It doesn't really answer my question because my point is that this shouldn't be happening at all! There are millions of people out there who bank online and there are millions of Firefox/Mozilla users. When you try to access your online bank account you should not get a response 'Secure connection failed' - this does not happen with any other site I access on a daily basis - just NatWest. There should be no 'secure connection' issues with regard to a national bank's website. Mozilla and/or NatWest should address this problem - it should not be down to their millions of users to try to find 'fixes'!

I emailed NatWest reporting this problem with the Chrome browser in mid July and again about a month later asking for an update, but I just got the reply "we are working on it" One work around is to use any other browser! It works fine in MS Edge for example. It's also worth noting that no other banking or credit card site that I use has any similar problem, it's confined to Chrome and FF plus the NatWest customer login for on line banking.

Many thanks for this solution. I note you are having this problem with Chrome but I am using Firefox! Without wishing to tempt providence it hasn't been quite so bad lately. l think it may help to use the 'Sleep' facility rather than logging off completely. Thanks again for your help!

markitzero said

Many thanks for this solution. I note you are having this problem with Chrome but I am using Firefox! Without wishing to tempt providence it hasn't been quite so bad lately. l think it may help to use the 'Sleep' facility rather than logging off completely. Thanks again for your help!

I was using FF until about 6 months ago, but then it started running extremely slow and freezing for minutes at a time. I tried all the usual fixes other than completely uninstalling it and re-installing, it was quicker to just switch to another, working browser. I suppose that I will get round to trying to fix it again sooner or later as there are some things it does better than Chrome. (and others worse!)

markitzero said

When you try to access your online bank account you should not get a response 'Secure connection failed' - this does not happen with any other site I access on a daily basis - just NatWest. There should be no 'secure connection' issues with regard to a national bank's website. Mozilla and/or NatWest should address this problem

Yes, unfortunately, it's more challenging for support volunteers and developers to solve issues that require an account, especially one where you need to deposit money.

markitzero said

I get this error message almost daily when I try to access Natwest. I know I can fix it by clearing cache but then I have to reset all the autofill data, re-enter search criteria, etc.

Are you using the "Clear Recent History" feature? That dialog has a Details button to show all the different categories of data. Try unchecking everything except Cache. Does clearing only Cache fix the problem by itself?

Another common issue would be the website's previously set cookies. You can clear those as follows:

While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "Clear Cookies and Site Data"
• (menu bar) Tools > Page Info > Security > "Clear Cookies and Site Data"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "Clear Cookies and Site Data" button

In the dialog that opens, you will see one or more matches to the current address so you can remove the site's cookies individually without affecting other sites.

Then try reloading the page. Does that help?

If we can isolate the particular data that breaks the connection, that might help discover why. Or maybe it won't help you and me, but it might help the bank.