Getting this error even after installing latest nightly build which Beat said had backup ca-cert:
HTTPS POST Connection to payment gateway server failed (check system information in CBSubs Settings): ERROR: cURL error 60: SSL certificate problem: self signed certificate in certificate chain ()
I saw in another thread that the latest nightly build should fix this, but I just confirmed that it's not fixed for me.
I reinstalled latest again (was same file though) this morning and still got this message. I'm goingto contact my host about ca-cert but thought I'd let you know.
CB 2.3, CBsubs 4.3, PHP 7.1, J! 3.9.X