I am sure that this error can occur when apache ssl virtualhost directive doesn't contain configuration on SSLCertificateFile. However, in my situation I am pretty sure I have it configured correctly as shown in my httpd-ssl.conf below:
LoadModule ssl_module modules/mod_ssl.so Listen 443 <VirtualHost *:443> DocumentRoot "/home/web/htdocs" ServerName mydomain.com ServerAdmin firstname.lastname@example.org ErrorLog "/usr/local/apache2/logs/error_log" TransferLog "/usr/local/apache2/logs/access_log" SSLEngine on SSLCertificateFile "/etc/pki/tls/certs/my.crt" SSLCertificateKeyFile "/etc/pki/tls/private/my.key" SSLCertificateChainFile "/etc/pki/tls/certs/intermediate.pem" SSLCACertificateFile "/etc/pki/tls/certs/ca.pem" </VirtualHost>
The certificate is properly configured with 644 permission while the private key with 600.
Did I miss anything?