[edcolon]

When you buy a CA certificate and install it in your server and enable it, Webservices SOAP sometimes don´t work.
Processmaker Error:
SoapClient::SoapClient(): SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed (line XXXX):

The fix (CENTOS 7, NGIX 1.16, PHP 7.1):
First run and see if there are errors:
curl --verbose https://subdomain.domain.com
There should be some problems with the Server Certificate.

Then you go:
ln -s /PATH_TO_YOUR_CERTIFICATE/your_certificate.pem /etc/pki/ca-trust/source/anchorsyour_certificate.pem
yum install ca-certificates (it should be installed within your system)
update-ca-trust force enable

Try again, it should be fixed.

Regards and have fun.

@Ed