I get "Invalid security certificate" message

This certificate message is MITM (Man-in-the-middle) protection. If you get this message, it means that some new certificate/application has been found on your device that has access to device traffic ( for example, anti-virus applications that need to monitor traffic to block threats) and is trying to stop access to a website.

As for how to view certificates, there can be numerous different ways (as the certificate is stored on the device), one of which is described here: https://codesigningstore.com/how-to-view-certificates-on-windows-10
Visit our official NordVPN blog to learn what you should know about web certificates in more detail and what you should do if you see a certificate warning.

Here's how your screen may look with the error message:

Browser displaying an invalid security certificate warning message

Investigating further, we can see that it's clear that the certificate details have changed since it's being interfered with. In this case, it was a Cisco firewall and the website is safe to acces:

Browser certificate details showing the certificate issuer changed to a Cisco firewall, indicating traffic interception

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I get "Invalid security certificate" message

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