How to fix the ERR_CERT_COMMON_NAME_INVALID error

Safety comes first when using the internet. The GDPR is not alone in offering protection to internet users against misuse and data theft, continued development in the technical structure of the internet ensures that you can surf in safety. To do this, current internet browsers are constantly improving their security features to protect their users. Secure data transfer using HTTPS connections has become a near-universal standard.

Google Chrome takes security very seriously. Because of this, you might receive an “ERR_CERT_COMMON_NAME_INVALID” error message when your browser tries to load a website. Find out what to do if this happens.

Surprisingly, this warning can also show up on websites that you know well and visit often. There can be several possible causes for this:

• The website has an incorrectly configured server, e.g., with a redirection to an insecure website or content.
• The website has an expired security certificate, as shown in the picture.
• Your computer’s security system “overreacted”, either the firewall or an antivirus program.
• Some browser plug-ins or extensions, generally made by third parties, can also cause this error message.

There are several techniques to find out the details behind the error and fix it in a targeted way. We’ll tell you about the most important ones here.

As a visitor to the website, you can’t do anything about poorly designed redirections on the web server which result in an “ERR_CERT_COMMON_NAME_INVALID” error. However, you can change how the site is accessed: Try typing the domain name of the website you want both with and without the “www.”.

To check if any browser extensions you may have are causing problems with the security certificate of the website you are visiting and giving you the “ERR_CERT_COMMON_NAME_INVALID” error, deactivate the extensions one by one until you are able to load the site without the error occurring.

Browsers and computers save security certificate data in caches. These may contain expired versions of certificates which can clash with a current, valid certificate.

You can choose various time ranges to clear the data beginning from.

When you click on “LAN settings” (1), another window opens. Make sure that the setting “Automatically detect settings” box (2) is checked.

Antivirus programs and firewalls are very useful tools to keep your computer’s data safe from outside attacks. However, both of them can block SSL certificates or override network settings, which can cause your browser to give you an “ERR_CERT_COMMON_NAME_INVALID” error. It might be helpful to temporarily deactivate these safety features to check if that stops the error message from appearing. You can access your firewall by searching “firewall” in Windows. You can find settings for your antivirus software in its help menu – this can vary from program to program.

Your computer’s time will now be compared with the “internal time” of your network provider, which means that is it very precise.

You can find public hotspots in many parts of the world. For most of them, you have to sign in before you can use them, and this sign-in tends to use an insecure connection. As a result, you won’t land directly on the sign-in page of the hotspot and will be unable to use the network. Instead, you will just get the “ERR_CERT_COMMON_NAME_INVALID” error message. If this happens, type an unsafe site address into your browser’s address bar, e.g., http://hotspot.tld (i.e., without the “s”) and load the site. You should then be able to access the sign-in page of the hotspot.

You should never hand over login data, payment details or other personal information on these websites. The “ERR_CERT_COMMON_NAME_INVALID” error message can also mean that you have come across a deliberate scam involving a hacked or redirected website. You should only visit unsafe sites if you are sure that you can trust the owner.

Restarting your computer deletes a lot of temporary data, including several temporary caches. This can fix the “ERR_CERT_COMMON_NAME_INVALID” error and many others. The same is true when you restart your internet router.