Site is reported (by some browsers) "not secure" though certificate hasn't expired

Question

I'm running a Wordpress site on Ubuntu 14. It's been secure for 23 months. But with 1 month to go, a few customers' Opera and Chrome browsers are refusing to report the site as secure. SSLLabs.com gives me a grade of A.

I could renew the certificate ... but suspect that wouldn't solve anything b/c this one has NOT expired and NOBODY claims it has.

Ideas?

Answer 1

New update Google Chrome 56, 57 doesn't trust some CAs, including StartCom https://security.googleblog.com/2016/10/distrusting-wosign-and-startcom.html

You should switch to other CA or use Let's Encrypt.