How to Resolve Comodo RSA Certificate Not Trusted Error

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Two methods to help you fix this complex Comodo SSL not trusted error

Unlike other SSL related errors, the “Comodo RSA Certification Authority Not Trusted” or “Comodo RSA Certificate Not Trusted” error doesn’t appear as frequently. However, as you’re reading this sentence right now, it’s likely you’ve come across it and it’s occupying your attention. Well, not for long. In this post, we’ll outline some simple steps that will make this error disappear out of your browser.

Let’s get started on fixing this Comodo SSL not trusted error.

The Reason Behind the ‘Comodo RSA Certificate Not Trusted’ Error

Wondering why your Comodo SSL certificate is not trusted? Let’s take a moment to imagine you’re a web browser (yes, we’re quite serious here). A user gives you the order to visit a particular website that has an SSL certificate installed on its web server. As a browser, you must identify the authenticity of the SSL certificate and of the certificate authority (CA) behind it. How do you do it? The answer is root certificates of certificate authorities. The browser companies have things called “root stores” where they store root certificates of various certificate authorities that fit the criteria of their root programs.

The Mozilla Project, used by Firefox and the Thunderbird email client, is an example of such program. Mozilla accepts certificates from the CAs who meet the requirements of the policies of this program. They also have the authority to remove a CA if it fails to meet those requirements. So, when you (the browser) come across an HTTPS-enabled website, you’re supposed to chain the SSL certificate to one of the root certs in the root store. That’s how you validate legitimacy of the SSL certificate.

Now, let’s come back to the “Comodo RSA Certification Authority Not Trusted“ error. When you visit a site on which this error comes up, what happens is that your browser is not able to link the SSL certificate of that website back to its root store. A very likely reason cause of this error is that you might have deleted the certificate from your browser’s root store unintentionally.

Here’s How to Fix Comodo RSA Certificate Not Trusted Error

There are two possible ways you can fix this error. The first one is finding out which root you’ve accidentally deleted and reinstalling it in your browser’s roots. The second one is deleting your browser and then reinstalling it. Let’s explore both of these methods in a bit more detail.

Method 1: Add the Missing Comodo Root to Your Browser

  • First, go to the website you’re having this error and click on the Padlock in the address bar.
  • Now, View Certificate Details and go to certification path.
  • Now, see the certificate listed on the top? That’s your root certificate.
  • Go to Comodo’s helpdesk, find out the missing root and download it.
  • Now, go to your browser’s HTTPS section and import the root certificate you’ve just downloaded.

On completion of these steps, the “Comodo RSA Certificate Not Trusted“ error should have been fixed.

Method 2: Delete Your Browser and Reinstall It

We don’t need to tell much about this, do we? One thing we’d like to point you out is to check whether your browser has important data/bookmarks/passwords, etc. stored in it. Be sure to save those in a Word document or another backup method to ensure you don’t lose them.

We hope this post helped you fix this pesky error and relieve all the headspace it had occupied.

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