Yes, I've followed all the steps mentioned in this link. Also troubleshooted the SSL Certificates And Keys and it works.
I've updated the SSLCertificateFile, SSLCertificateKeyFile and SSLCertificateChainFile.
After that I also restarted the Apache, and its successfully started at my end.
But still I'm getting the NET::ERR_CERT_AUTHORITY_INVALID error on my website.
Here is the website domain: https://internease.com
Please have a look into this.