elcapitan old certificates and access to the xojo forum ?

anyone has problems to access this forum using el capitan since today ?
I am.
it is not working (message saying your connexion is not secure) from other elcapitan, it is ok using firefox but not using safari or opera
it works nice using 10.13 or later.

seems to be a root certificate that has expired.

Last FireFox / El Capitan works OK for me.

On Safari, I get “This connection is not private” error message…

A number of old AddTrust roots expired today. Apple doesn’t maintain the roots for old versions. I was just dealing with this a couple days ago. 10.13’s roots haven’t been updated in two years, for example.

Edit: Firefox bundles its own root certificates. It wouldn’t surprise me if Chrome does too.

I’ve found the new certificates to install. will report here once it works.
I would like to still use 10.11, it will be obsolete in a few months, but hey at least until xojo wants a 10.12 ?
10.11 is the last os that doesn’t have any over the top useless “security” features…

well it seems ok
after adding these certificates :

COMODORSAAddTrustCA.crt InCommonRSAServerCA_2.crt SectigoRSADVBundle.pem SHA-2 Root USERTrust RSA Certification Authority.crt
found on these pages
https://spaces.at.internet2.edu/display/ICCS/InCommon+Cert+Types
https://support.sectigo.com/Com_KnowledgeDetailPage?Id=kA01N000000rfBO

and “always trusting” them in get info of each certificate in the keychain app

more detailed explainations here :
https://calnetweb.berkeley.edu/calnet-technologists/incommon-sectigo-certificate-service/addtrust-external-root-expiration-may-2020