News, Information and Resources about SSL Certificates
Authorized Reseller


A brief guide to fix an SSL Common Name Mismatch Error: NET::ERR_CERT_COMMON_NAME_INVALID

SSL error is also referred to as SSL connection error. The SSL is initials for Secure Sockets Layer. It is an error which may appear when one attempts to get a secure connection in a website server. Usually, the SSL error is a result of crummy executions of SSL Certificates.  This results in the text being displayed in the when loading the website.
cheapest ssl certificate


ERR_CERT_COMMON_NAME_INVALID also known as SSL Common Name Mismatch Error is one of the SSL errors. It can be a consequence of misconfiguration of certificate in a server. It can also be caused by a third-party extension. It can also be caused by security programs in a computer among them being antivirus and firewall. The SSL common name mismatch error may appear as below screenshot.

Common Name Invalid SSL Error


When fixing the SSL error, it is paramount to identify the cause of the error. By identifying the cause of SSL common name mismatch error, the below techniques can be used to resolve the error.

Check date and time are correct

If the date and time are not properly set on your desktop, then your browser (chrome) will show ERR_CERT_COMMON_NAME_INVALID. You can fix the error by adjusting time and date on your PC.

Find out problematic extensions

First, we need to turn on Incognito mode in browser lets say chrome browser and check if the error persists or not. If the error is solved then there is no need to look for bad extensions but in another case, you should check one by one extension.

To do so, you need to disable all extensions which can be found in Click three dots >> More Tools >> Extensions. After that, trigger single extension and watch if the error goes by browsing website. Follow this process until you find a culprit extension. Once you find such an extension, you should delete it from a browser and fix the error.

Confirm that the correct certificate is installed

An SSL common name mismatch may occur between the domain and the certificate and this happens when you have installed the correct certificate, but the certificate does not cover the typed web address in the browser. There may be a different certificate installed on the domain name. This mismatch will result in “NET: ERR_CERT_COMMON_NAME_INVALID” this can be checked by confirming “issued to” domain information to the domain certificate.

As this error happens due to a mismatch between the domain and the certificate. , you need to check that the browsing domain and subdomain should be covered under SAN and wildcard certificate. SAN certificate counts each domain separately and wildcard certificate covers single-level subdomains. So if you are browsing domain or subdomain which is not covered by your certificate, then it may show an error.

Check for redirects and Non-WWW vs. WWW

It is not all SSL certificate that covers both non-WWW vs. WWW accounts of the website by default. You should stop redirection to www to Non-WWW or Non-www to WWW depend upon the domain you entered while purchasing the certificate. It is thus vital to confirm whether one’s browser is redirecting visitors compellingly to another part of the website. If so, adjustments should be made on the settings to eliminate the redirect.

For example, if you purchased wildcard SSL and if the main domain like is redirecting to then it will show error in the browser. In this case, the redirect is necessary it’s needful to get another SSL certificate to cover the redirecting of traffic to the domain of choice the error.

Check the site address is appropriate

One may change the site protocol to a secured HTTPs from unsecured HTTP due to curiosity. When one saves changes and the site has no SSL certificate either installed or bought, the site protocol is changed, causing “NET: ERR_CERT_COMMON_NAME_INVALID.”  If one has WordPress, it is recommended not to put “S” before HTTP if the certificate has not been bought or and installed. It is appropriate to move back to WordPress account general settings and check the URL.

wordpress https settings

Clear SSL State

SSL common name mismatch error can be resolved by clearing if SSL cache is there. The following procedure can be used to correct the error. Open the internet properties then go to the content tab, then clear SSL cache, you click, and the error is resolved. On the chrome browser the process is as follows, go to settings, then show advanced settings, after that on the Change Proxy Settings click on the clear the SSL state and SSL common name mismatch error is corrected.

Clear SSL State

Check proxy settings:

If your proxy setting is not set to Automatically detect settings, you may face error and affect your browsing experience. This will restrict you to surf websites on your browser.

To solve it, you need to browse Internet properties by right-clicking on the Network Access icon and go to internet settings.

Here, you need to tap on Connection and click on LAN Settings.

internet properties - connections

Then, you will have a box where you need to check the box against “Automatically detect settings” and press the OK button.

local area network (LAN) settings

Now, check whether the error is solved or not. If not, you can try the next point described here.

OS & Browser should be up-to-date

The old or outdated browser and operating system frequently show such type of error and to outcome from this issue, you can update windows OS and update your browser. As there are new patches from developers rule out in available updates and that might be a cause pertaining to show such error. In case, if you are website owner, you should hear other users, if they are facing the same error then you should update your browser and OS also.

Self-signed certificate and different domains

This type of event happens when the SSL certificate is assigned to a different domain name or self-signed certificate is attached to that domain name. In the case of a self-signed certificate, which is used for internal server purpose, it will reflect error as most browsers do not trust the self-signed certificate as a legit certificate. You need to contact the developer to remove self-signed SSL and install new SSL on a domain. This, in turn, fixes the ERR_CERT_COMMON_NAME_INVALID problem.

Check for Antivirus/Firewall

It might be happening that antivirus is blocking SSL connection, be sure it should not be check marked with disabling https scanning in antivirus software. If you do not find such an option, then turn off software.


Websites are the gateway through which customers and the world at large get information about products offered. The most unfortunate thing in seeking information is when the very sought-after information is not accessible. The ERR_CERT_COMMON_NAME_INVALID is a challenge that can be resolved with a click of a mouse. The various steps enumerated above are very helpful in keeping information streaming to the intended recipients and the world at large.

Related Articles: