When you enter your domain name with https in the address bar (https://your-domain-name.com) you get an error like below
Your connection is not private
Attackers might be trying to steal your information from your-domain-name.com (for example, passwords, messages or credit cards).NET::ERR_CERT_AUTHORITY_INVALID
This server could not prove that it is your-domain.com; its security certificate is not trusted by your computer's operating system. This may be caused by a misconfiguration or an attacker intercepting your connection.
The browsers are configured to accept the certicates only from certain trusted authorities. In your case, either the certificate is signed by yourself but the browser does not know you. Or it is signed by a third party that your browser does not trust. Maybe the certificate authority was trusted by browser when you initially got the certificate but are no longer trusted due to malpractices. To fix this, please get a new certificate from a trusted authority.
If you are not sure which authority to use, we recommend Let's Encrypt. It is a non-profit trusted authority who issues certificates for free. Their goal is to make the internet safe for all users
If you use Apache in your server, please follow this guide How To Secure Apache with Let's Encrypt on Ubuntu 18.04
If you use NginX in your server, please follow this guide How To Secure Nginx with Let's Encrypt on Ubuntu 18.04 or Configuring your server to provide HTTPS using Let's Encrypt and Nginx
If you have any issues and are not able to figure it out, we are here to help. Please email to firstname.lastname@example.org or use the chat window at the bottom and we will help you.
Firefox Error Message
Firefox is another browser, just like Chrome. The same problem causes a slightly different error message. The above fix helps for firefox browsers too. If you do not use Firefox, you can skip this part.
Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for your-domain-name.com.
Error code: MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT