Constant Not secure error messages

Lbrewer42

Almost every webpage is telling me it is not a secure connection - even this one!
I was only able to get here using a Private Window.

This started 2 weeks ago using Brave browser. I switched to Opera, various others, and ended up in Vivaldi.

Using OS X Yosemite on MacBook Pro 13 inch Mid 2012. Cannot upgrade b/c I need to use iWork Pages '09 b/c the next version was dumbed down badly and Pages '09 cannot run on anything past El Capitan (and this takes a work around).

This site gave an error of:
*"Your connection is not private
Attackers might be trying to steal your information from login.vivaldi.net (for example, passwords, messages, or credit cards). Learn more
NET::ERR_CERT_DATE_INVALID

login.vivaldi.net normally uses encryption to protect your information. When Vivaldi tried to connect to login.vivaldi.net this time, the website sent back unusual and incorrect credentials. This may happen when an attacker is trying to pretend to be login.vivaldi.net, or a Wi-Fi sign-in screen has interrupted the connection. Your information is still secure because Vivaldi stopped the connection before any data was exchanged.

You cannot visit login.vivaldi.net right now because the website uses HSTS. Network errors and attacks are usually temporary, so this page will probably work later.*"

Other sites tell me certificates have expired, when they have not.

I just tried to open this site in another Private Window and this time it would not allow me to click past, but after hitting the advanced option, it would not give the option to advance anyway.

It al seems to random! I have added certificates and it got me into eBay at least.

Installed HTTPS everywhere - it makes it harder to get into websites! Ones that did work now won't!

Please help!

Oh - I also took the learn more link in the first error message above - nothing works.

What is going on here? What has changed - especially after the complete clean installation of the OS, it seems to me it is outside my computer.

Chas4

Try this: updating the LetsEncrypt root certificate manually install the certificate. https://docs.certifytheweb.com/docs/kb/kb-202109-letsencrypt/

tonyd1

For older macOS not updated by Apple:

Download the ISRG Root X1 certificate file from http://x1.i.lencr.org/
Open the Keychain Access app and drag that file into the System folder of that app.
Find the ISRG Root X1 certificate in System and double click on it, open the Trust menu and change "Use System Defaults" to "Always Trust", then close that and enter your password to confirm the change (if prompted).

DoctorG

@tonyd1 https://forum.vivaldi.net/topic/67111/fix-let-s-encrypt-certificates-out-of-date-since-end-september-2021/5