hi, please give us more information about the error by clicking on the error code, copying the text to the clipboard and then pasting it here into a reply in the forum as shown in the screenshot.

thank you!

How to troubleshoot security error codes on secure websites

Well, below is a response to the weather network web site. The same applies to every of my old and new attempts to open some web page. To be clear, I didn’t touch any setting (like virus protection program – Kaspersky). Firefox has been working perfectly for years. Yesterday I turned off my computer at noon and then turned it on 3 hours later. I tried to open Firefox but immediately I got that “updating message” and few seconds later, when Firefox launched, it couldn’t open my home web page. Again, I haven’t touch any settings on my computer. Any change came with your update. But now even the previous version (57.4) doesn’t work.

Regards, Peter

Here is the copied clipboard:

https://www.theweathernetwork.com/weather/canada/ontario/ottawa/k1v9p6/E1786210

Peer’s Certificate issuer is not recognized.

HTTP Strict Transport Security: false HTTP Public Key Pinning: false

Certificate chain:

ok, then please try to set-up kasperksy as it's described in How to troubleshoot security error codes on secure websites

Yes, when I disabled the scanning encrypted connections it started to work. Before Kaspersky scanned encrypted connections upon request from protection components. But it worked with all previous Firefox versions!! So, why are you introducing such changes?

I suspect Kaspersky is the problem here not FF since it worked in previous version. I use Defender and Windows Firewall and have no such problems as your describing.

See also:

• bug 1433065 - Firefox 58 is not loading any pages (including about: pages)

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)