Recently we encountered an issue whereby it’s not possible, with any browser, to login to the Yealink WebGUI thus not able to properly configure the IP-Phone. The error is that “Your connection is not private” and even when clicking “Advanced” it will not allow you to go to the login page of the IP Phone.
Of course, the 1st place to search is the manufacture FAQ and KB but to my disappointment, there was no real answer there and the available articles looked way too complicated, creating new Certs, upload them to the phone and browser, etc, It gave me a headache just reading it. All I want to do is just set the extension and SIP details. -simple-
Long story short I Googled a bit more and found this excellent solution to bypass this restriction.
When browsing to the Yealink WebGiu page and after clicking “Advanced” click somewhere in the browser window itself -to make it the active window- and type thisisunafe and enter and the login page will pop-up.
The original article is from Dejan Blazeski and can be found here.
Hope this helps you as much as it did us.