Hi!
I'm trying to establish an HTTPS connection to the customer's endpoint via APEX (using REST)
Until 11 February I had no problems and I called the service correctly, on 12 February the certificate expired. After a couple of days the certificate has been updated by the customer but I get this exception:

System.CalloutException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

The certificate is signed by the CA: Thawte RSA CA 2018

I don't know how to manage it..