As of 2018-03-11 I have was having issues with using a Lets Encrypt SSL certificate on my N2WS CPM server. I found that the apache server was not providing the intermediary certificate when provided in a chained format in “SSLCertificateFile /opt/n2wsoftware/cert/cpm_server.crt”. To resolve the issue I explicitly provided apache with the location of the intermediary certificate by adding the following configuration line to /etc/apache2/httpd.conf ;
SSLCertificateChainFile \ /etc/letsencrypt/live/SUB.DOMAIN.TLD/chain.pem