How to fix the `MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE` error

Infos

Dieser Artikel behandelt AdGuard für Windows, einem multifunktionalen Werbeblocker, der Ihr Gerät auf Systemebene schützt. Um zu sehen, wie es funktioniert, laden Sie die AdGuard-App herunter

Some users of AdGuard for Windows with enabled HTTPS filtering are unable to access certain websites like google.com and youtube.com. Instead of opening a website, browsers with Strict Certificate Pinning would display a MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE error.

Here is a list of impacted browsers:

Arkenfox
Brace
Cachy Browser
Dove
FireDragon
LibreWolf
Mull
Mullvad Browser
Phoenix
Tor Browser

If your default browser is one of these, do the following to solve the problem:

Type about:config in the address bar of your browser
In the menu that appears, enter security.cert_pinning.enforcement_level in the search field.
Change the security.cert_pinning.enforcement_level parameter from 2 to 1.