12 Proven Ways to Fix NET::ERR_CERT_COMMON_NAME_INVALID Error

NET::ERR_CERT_COMMON_NAME_INVALID is an error that occurs in web browsers when the domain name and common name are mismatched. A common name is the fully qualified domain name (FQDN) of the SSL Certificate.

SSL certificates are issued to initiate HTTPS protocol. The protocol is responsible for encryption functions. Through encryption, all communications and data transfers between web servers and web browsers ensure a secure connection.

The misconfiguration could raise concerns about the authenticity and security of the website. This article covers the details of NET::ERR_CERT_COMMON_NAME_INVALID SSL error, how it occurs, and top tips to solve it. Read on to know more.

What is NET::ERR_CERT_COMMON_NAME_INVALID Error?

The NET::ERR_CERT_COMMON_NAME_INVALID error takes place when the domain name a user is trying to access does not match the common name (CN) or any of the Subject Alternative Names (SAN) on the site’s SSL certificate. This is why the error is also called the SSL common name mismatch error.

 Browsers react to this discrepancy by warning users that the connection might not be private and that users might be trying to steal their data. Let’s see how it appears in popular browsers.

NET::ERR_CERT_COMMON_NAME_INVALID Error Across Different Web Browsers

1. Error in Google Chrome Browser

In Google Chrome, the message; Your connection is not private appears followed by NET::ERR_CERT_COMMON_NAME_INVALID. 

Additionally, the Chrome browser warns visitors that attackers might be trying to steal their information through the website. Chrome provides examples of such information, including passwords, messages, and credit cards. It also gives users an option to report such incidents to Google. Users can choose to exit the website or continue browsing by clicking on Advanced. 

2. Error In Mozilla Firefox

The message; “Warning: Potential Security Risk Ahead” appears for Mozilla Firefox. The browser further tells users it has detected and cannot proceed with processing their request. It cautions users that proceeding to the site might lead to attackers stealing their information. Firefox gives examples of such information as passwords, emails, and credit card details.

As you will notice from the screenshot above, Firefox does not show the code for the common name invalid error. Instead, the browser tells web visitors what has happened with their connection. Users can click on Learn more… to get solutions to the problem.

3. Error In Safari Browser

On the Safari browser, the error appears with the message: “Safari can’t verify the identity of the website.” This message is usually followed by the domain name of the website. See the attached screenshot:

4. Error In Microsoft Edge

When you get a “NET::ERR_CERT_COMMON_NAME_INVALID” error in Microsoft Edge, a big red warning page pops up saying your connection isn’t private. It also shows a code (NET::ERR_CERT_COMMON_NAME_INVALID) to help you fix the problem.

Error In Internet Explorer

Internet Explorer goes straight to the point with a warning: “This site is not secure.” It further explains the meaning of this. “This might mean that someone’s trying to fool you or steal any info you send to the server. You should close this site immediately.

Common Reasons Behind the NET::ERR_CERT_COMMON_NAME_INVALID error

To know the causes of NET::ERR_CERT_COMMON_NAME_INVALID error, you first need to understand how the concept of a common name applies to SSL certificates. SSL certificates are issued to initiate HTTPS protocol. The protocol is responsible for encryption functions. Through encryption, all communications and data transfers between web servers and web browsers are deemed secure and impenetrable. It will take hackers trillions of years to crack an SSL encryption.

Certificate Authorities usually issue SSL certificates to specific domain names. If the specific domain name does not align (fails to match) with the issued certificate, the NET::ERR_CERT_COMMON_NAME_INVALID error occurs. This explains why the error is sometimes called the SSL common name mismatch error.

Please note: The NET::ERR_CERT_COMMON_NAME_INVALID error does not only occur because of a common name mismatch.
There are many other reasons that might cause this error. Please note that the error’s cause might be browser-based or server-based. Here are some of the causes of the error:

1. Domain name mismatch: This is by far the most known cause of the NET::ERR_CERT_COMMON_NAME_INVALID error. Domain name mismatch is somewhat self-explanatory. If the domain name in the URL does not match the common name (or subject alternative name), we call that a domain name mismatch, which could result in the error.
2. The SSL Certificate Issued To A Different Domain: If the SSL certificate is issued to a different domain, then using it on an alternative domain could result in an error. For instance, if a certificate is issued for www.abcde.com and you use it on www.12345.com, the error is bound to occur.
3. Expired Certificate: An expired or misconfigured certificate could result in an error.
4. Using a Non-Fully Qualified Domain Name: Using a non-FQDN, such as a local host or internet server name, could be the culprit causing the error.
5. Interference from Third-party Browser Extensions: Extensions that manipulate internet connections, such as ad blockers, VPNs, and security plugins, could alter the certificate and cause a mismatch.
6. Obstructions from Antivirus: Some antivirus software comes with advanced features, such as scanning HTTPS sessions. These features substitute the servers’ certificates with other certificates. This could cause a mismatch and interfere with the handshake process.
7. Corrupted Browser Cache and SSL State: If you update your certificate but the browser still holds the old certificate in the cache, then a mismatch is bound to occur, and consequently, the NET::ERR_CERT_COMMON_NAME_INVALID error.

How to Fix NET::ERR_CERT_COMMON_NAME_INVALID Error?

At this point, it is crystal clear that many factors contribute to this error. This makes it difficult to narrow down to a specific cause and align a tailored solution. There are several troubleshooting solutions you can try out to resolve this error. This section covers the 12 most effective tips to fix the NET::ERR_CERT_COMMON_NAME_INVALID error.

1. Verify SSL Certificate Details

There is no doubt that the most common cause of the error is the mismatch between a website’s domain and a common name. To avoid this error, you must start by ensuring you install the right SSL certificate that aligns with your domain name. You should also configure the certificate appropriately. Here is how to do that in Chrome:

Step 1: Click on the tune icon on your website.

Step 2: A dropdown menu will appear. Click on connection is secure.

Step 3: Select Certificate is valid from the menu.

From here, ascertain whether the actual domain name is in sync with the common name attached to the certificate. If they do not sync, it means there is a common name-domain name mismatch. You will need to install a fresh certificate.

For Wildcard SSL certificates, the error might signify the certificate does not cover the subdomain you are accessing. Wildcard certificates cover the main domain and several subdomains under the parent domain. It is possible to have a common name listed as a subdomain.

For multi-domain (subject alternative name) SSL certificates, you will have to dig deeper to verify the certificate. SAN certificates cover multiple domains within a website. The certificate covers top-level domain variations, www, non-www, and subdomains. You can verify the details by clicking on the certificate window and the details. Choose the extension Subject Alternative Name label. You can then see a list of all the domains the certificate covers.

2. Update Your Web Browser and Operating System

Updating your operating system and web browsers ensures software stability. Software and OS stability could help minimize a lot of errors including the NET::ERR_CERT_COMMON_NAME_INVALID error. 

Update Web Browser

Follow the below steps to check for updates in your browser (chrome).

Step 1: Click on the three dots in the top right corner. Hover to the Help bar and Click on About Google Chrome.

Step 2: The settings panel will open. From here, you can check whether your browser is up to date.

Step 3: In case your browser is not up to date, you can click on Update Google Chrome to update it.

Update Operating System

For your operating system, you can follow these steps to update:

Step 1: Click on the Start bar on your computer and select Settings.

Step 2: From the settings panel, click on Windows Update. From here, you can proceed to check if your operating system is up to date. You can also download and install any available updates.

3. Check for Self-Signed SSL Certificates

SSL certificates are acquired from reputable certificate authorities. The certificate authority signs the certificate before issuing it to the users. That is not the case with self-signed certificates. Self-signed certificates are mere creations of users and are not issued by authorized CAs.

Self-signed certificates do not offer full encryption like that from CA-backed certificates. As such, most web browsers will flag websites using them as “insecure.” Some browsers may display the NET::ERR_CERT_COMMON_NAME_INVALID error in cases of self-signed certificates. You can rectify the error by deleting the self-signed certificate and acquiring one from a reputable CA.

4. Check and Rectify All Misconfigured Redirects

Redirecting your site without an SSL certificate can cause this error. Not all certificates cover www and non-www domain variations by default. So before purchasing an SSL, you must check to ensure it covers both www and non-www domains. You can also alter the certificate’s common name to solve the error.

Moreover, you can get a SAN (Subject Alternative Name) certificate that includes both domains or an extra certificate for the domain you’re rerouting from. To safeguard subdomains using wildcard domains, make sure you list them all rather than rerouting traffic between them. Another option is to use several available tools to check if your site is directing users properly.

5. Configure URL Settings In phpMyAdmin

URL variations between option values in home rows and siteurl could be the culprit that cause this error. In such a case, you will need to revise the URL settings of your WordPress. You can do so via phpMyAdmin. Here are the steps:

Step 1: Open phpMyAdmin application on your web hosting account.

Step 2: Select the database of your website and look for the wp_options table. Find the home and siteurl in the table and ensure they redirect to the same URL.

6. Align Your WordPress Address and Site Address for Consistency

It is possible to mistakenly migrate your website’s address to HTTPS without an SSL certificate. This is a common occurrence in WordPress and could lead to the NET::ERR_CERT_COMMON_NAME_INVALID error. 

Fixing this is simple. Open your WordPress dashboard and go to settings. Click on General. Confirm whether your WordPress address and website address are similar.

If the URLs use HTTPS in the absence of an SSL certificate, you will need to change them to HTTP.

7. Clear Browser Cache and SSL State

An outdated cache might load an older website version, resulting in the NET::ERR_CERT_COMMON_NAME_INVALID error. To prevent this error, you will need to clear the cache. Here are the steps to clear the browser cache in Chrome. 

Step 1: Click on the vertical dots in the top right corner of the browser.

Step 2: Select Clear browsing data, alternately, you can press Ctrl+Shift+Del.

Step 3: From the dialogue box, select the time range with which you wish to clear data. Click on clear data.

In an attempt to speed things up, browsers might cache SSL certificates. The browser ends up failing to fetch the latest certificate version. This could result in an error. To resolve this on Windows OS, you will need to clear the SSL state. Here is how to do that:

Step 1: Search for Internet Options from the search button on the taskbar. Click enter

Step 2: Click on the Contents tab and then on the Clear SSL State option.

8. Temporarily Disable Antivirus or Firewall

Antivirus software comes with an SSL scanning feature. Such software might sometimes block users from accessing HTTPS websites, leading to an error. You should disable the antivirus software to resolve the error. However, you should only do so if you trust the website. Antivirus software is important, and disabling it could jeopardize website security.

Here is how you can disable antivirus software:

Step 1: Click on the Settings tab on the Start tab

Step 2: Go to Update & Security and then click on Windows security.

Step 3: Click on the Virus and Threat Protection tab. Navigate to Manage Settings. Find Real-time protection and turn it off.

9. Evaluate Your Proxy Configurations for Potential Discrepancies

Misconfigurations in the proxy settings can lead to restrictions on web access. This could cause SSL errors, including the NET::ERR_CERT_COMMON_NAME_INVALID error. You will need to reset your proxy configurations to resolve the error. This process varies depending on the operating system you use. 

Follow the below steps to access proxy settings on Google Chrome.

Step 1: Open Settings by clicking on the three dots in the top right corner.

Step 2: Click on System, and click on Open your computer’s proxy settings.

For Windows users, the prompt will open the window for Proxy. You can proceed to alter the setting by clicking the option for Automatically detect settings.

10. Resolve Browser Extension Interference

Too many browser extensions might cause a host of issues due to extension conflicts. Such conflicts could lead to a common name mismatch, which results in the NET::ERR_CERT_COMMON_NAME_INVALID error.

To check whether the error is a result of extension conflicts, try accessing it from an incognito. If the website loads, the error may result from an extension conflict. To resolve this, you must disable extensions one after the other. If the site works in the absence of a disabled extension, then you have to delete it. The extension is the culprit.

Step 1: Go to settings and click on Extensions.

Step 2: From the dropdown menu, click on Manage Extensions.

Step 3: Find the extension you want to remove and click on Remove.

11. Change Your LAN Settings

The purpose of proxy settings is to route web traffic. Routing helps to protect website visitors from hackers. Any proxy misconfigurations might result in SSL errors. You might have to change LAN settings to resolve such errors. Perform the following steps to change the LAN settings.

Step 1: Search for Internet Options from the search button on the taskbar. Click enter

Step 2: Click on the Connections tab and select LAN settings.

Step 3: Ensure the Automatically detect settings box is checked. Save the changes by clicking on OK.

12. Check Date And Time Are Proper

An incorrect date and time on your PC could result in the NET::ERR_CERT_COMMON_NAME_INVALID error. Check to see if the date and time are proper. You can adjust the date and time by going to the Windows setting, selecting Time and Language, and the Date and Time.

You can either choose to set it up automatically or manually. 

Effective Strategies to Prevent NET::ERR_CERT_COMMON_NAME_INVALID Issues

Prevention is far better and cheaper than cure. Here are three key strategies to help you avoid the NET::ERR_CERT_COMMON_NAME_INVALID error.

1. Effective SSL Management

Most causes of the error occur as a result of poor SSL management. Webmasters can do better to prevent this error by having effective SSL certification measures. For instance, you must always ensure the certificate is up-to-date. Ensure you renew your certificate before it expires. Automating the certificate renewal process could save you a big deal.

2. Proper Configuration

Your web server and SSL certificate should be properly configured at all times. Ensure the virtual host is properly set up. It is also wise to test the server compatibility with your SSL protocols.

3. Ensure Accurate DNS and Server Configuration

Ensure that the server configurations and DNS settings are correct and consistent with the domain names listed in your SSL certificate. Be sure to make regular checks to ensure your domain resolves to the correct server and that all subdomains are properly configured. Accurate DNS and server settings help maintain certificate validity and prevent errors.

Conclusion

The NET::ERR_CERT_COMMON_NAME_INVALID error can be so frustrating. It can also be complex to fix, especially when you do not know what it is. You will need to narrow down and discover what is causing the problem. You should start by checking whether the common name in your certificate and the domain are the same. You can then move on to apply troubleshooting solutions covered in this article. The article has provided you with everything you need to know about the error. We hope it helps you solve the error.