Certificate problem

Hi all,

As of yesterday, I've been receiving the following error in Chrome, Firefox, and Safari:

NET::ERR_CERT_DATE_INVALID

I can proceed to the site, but I keep getting the error and I can't seem to save any new information in any field (which makes adding anything exceedingly difficult).

For your reference, I'm on a Mac, running El Capitan, version 10.11.6, and the latest version of Chrome. (I've also had this problem with several other sites, including Wikipedia!)

What's going on and can it be fixed?

Thanks,
Ms.LibraryCat

p.s. I couldn't even post this bug message from that computer--I had to use a different computer, one that I don't usually catalogue from.

>1 Ms.LibraryCat: A known (and not very well advertised) issue with older macOS computers - see https://www.macintouch.com/post/18319/apple-security-certificate-issue/

Thanks for the info. My mac *is* really old, so this makes sense. I'm not a real techie, but do you know if there are any fixes?

The only fix, I believe, is that you'll need to update your operating system. El Capitan is "end-of-life" status since around August 2018, to my knowledge (https://en.wikipedia.org/wiki/OS_X_El_Capitan).

>4 kristilabrie: If you are able to update. My old iMac (20" mid 2007) is stuck on El Capitan; it was too old to upgrade further.

(This may explain the connection issues we've been getting since last week - the newer machines use the old iMac for various ebook bits and bobs - Kindle 1.17, ADE 2.)

>3 Ms.LibraryCat: Follow the instructions at https://docs.certifytheweb.com/docs/kb/kb-202109-letsencrypt/ (about 2/3 of the way down):

macOS, iOS etc#

Some operating systems hold onto the expired R3 > DST Root CA X3 chain even if your server is no longer using it. Try a restart of the affected client device.

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).

>6 rodneyvc: Thanks rodneyvc! I actually found this info on a different forum and it totally worked! But I appreciate hearing it from a second source. It's a HUGE relief since I'm using a totally ancient iMac--but I figure since it's still working--it's a tank--why not get the very last drop of usefulness out of it as I can. For a minute there I thought it was paperweight time...but through the MAGIC spell you recommended, I think I can get just a bit more out of this old clunker. :)