Secure CWP ports

Hello folks!

I have created subdomain like server.domain.com. Also installed SSL Let's Encrypt for server.domain.com. Now I wan to select these certificates for CWP ports and services:  443, 465, 587, 993, 995, 2031, 2083, 2087, 2096.

The location of my ssl files for subdomain is:
SSLCertificateFile: /etc/pki/tls/certs/server.domain.com.cert
SSLCertificateKeyFile: /etc/pki/tls/private/server.domain.com.key

So I replace destinations in /usr/local/cwpsrv/conf/cwpsrv.conf:

from:
ssl_certificate     /etc/pki/tls/certs/hostname.crt;
ssl_certificate_key /etc/pki/tls/private/hostname.key;

to:
ssl_certificate  /etc/pki/tls/certs/server.domain.com.cert;
ssl_certificate_key /etc/pki/tls/private/server.domain.com.key;

But command "service cwpsrv restart" fails with the following error:
cwpsrv: [emerg] SL_CTX_use_PrivateKey_file("/etc/pki/tls/private/server.domain.com.key") failed (SSL: error:0B080074:x509 certifi...

Could anybody help me or show me tutorial for this? I have also researched but there's no tutorial like this.

Thank you in advance!

SOrry! I found that: http://forum.centos-webpanel.com/ssl/setup-ssl-for-hostname-working/ this workaround is OK and is still working. Thank you!