# Solved: NET::ERR_CERT_COMMON_NAME_INVALID

## Problem

`NET::ERR_CERT_COMMON_NAME_INVALID` error when opening your website.

### Cause of the problem

A `NET::ERR_CERT_COMMON_NAME_IN` error occurs when the domain the SSL
certificate is installed on is not listed on the certificate (either as the
common name, subject alternative name or covered by a wildcard).

## Solution

### Check if the domain has the correct certificate installed

The most common reason for this error to occur is installing an incorrect
certificate to a domain. The easiest way to check whether this is to inspect the
certificate and compare the `issued to` domain information to the domain the
certificate is installed on.

### Check redirects and www vs. non-www

Check if the browser is not redirecting users to the other version of your
website. Then check if you're forcing the traffic through the www version of
your domain. Some certificates don't cover www versions along with non-www
versions.