PHP - SSL certificate error: unable to get local issuer certificate

I'm running PHP Version 5.6.3 as part of XAMPP on Windows 7. When I try to use the Mandrill API, I'm getting the following error: > Uncaught exception 'Mandrill_HttpError' with message 'API call to messages/send-template failed: SSL certificate problem: unable to get local issuer certificate' I already tried everything I read on StackOverflow, including adding the following to the php.ini file: curl.cainfo = "C:\xampp\php\cacert.pem" And ofcourse downloaded to that location the cacert.pem file from http://curl.haxx.se/docs/caextract.html but after all that, restarted XAMPP and Apache server but still getting the same error. I really don't know what else to try. Can anyone advise on what else can I try?