RESOLUTION
To install Comodo "intermediate CA" Comodo ca-bundle certificate which was attached to your email in zip file along with certificate itself should be uploaded to the VE manually. For example to:
/etc/httpd/conf/ssl.crt/comodo-bundle.crt If you do not have ca-bundle certificate you may download it from Comodo site using this link: http://www.instantssl.com/ssl-certificate-support/cert_installation/bundle.crt
You can also get to that link at the Comodo.net website:
1. click menu Support > Product Support
2. choose 'SSL Certificates'
3. click on 'Installing a Certificate' link on the left menu
4. in the middle of that page you will see "
All the rest actions could be performed through HSPcomplete Control Panel:
i) install certificate through 'Secure Website' tab at 'Control Panel Home > Site > Website Management > WEB_SITE_NAME > Website Settings';
ii) check that SSL files were installed successfully and click on 'Enable SSL button' at 'Secure Website' tab;
iii) at 'Custom settings' tab on screen 'Control Panel Home > Site > Website Management > Website Settings' click on 'Edit' button and add the following line (assuming that ca-bundle certificate was saved as
/etc/httpd/conf/ssl.crt/comodo-bundle.crt inside VE):
SSLCACertificateFile /etc/httpd/conf/ssl.crt/comodo-bundle.crt After that click on 'Update' button.