we could not verify the certificate: reason = untrusted (Web Configurator Cause)

SierraTech

Here is an issue that prevents the possibility to setup a new ZYXEL Router on a Windows 10 or Windows 11 machine.

My original workaround was to use an older Windows 7 x32 laptop with Chrome or Firefox. I never received the option to click "Advanced" proceed to the website due to this error.

ZYXEL Support found article below:

Turns out I have to disable VIPRE Advanced Security in order to access Web Configurator. I have been dealing with this for 6 months, having to use my old laptop to get around this issue. I felt this is important enough to post here. I will file a report with VIPRE Support and see if there is a method to WHITELIST the ZYXEL Router.

https://www.sonicwall.com/support/knowledge-base/we-could-not-verify-the-certificate-reason-untrusted-error/230429125528410/

jasailafan

ZYXEL firewall uses a self-signed certificate, so you need to install a valid 3rd party certificate with full chain to the firewall. In this post, you can find how to import root certificate, intermediate certificates and end-entity certificate to the firewall.

https://community.zyxel.com/en/discussion/12686/usg-ipsec-as-remote-client-possible-to-import-a-certificate