Mail in High Sierra is not compatible with security keys


macrumors newbie
Original poster
Nov 4, 2018

I'm using High Sierra on an iMac late 2009. I have all the latest updates installed and I'm able to use my Yubikey 5 NFC with Safari. But when I activate the Advanced Protection Program in gmail, I need to signin again in Mail and the pop-up shows a message "this browser is not compatible with security keys", so I'm not able to read the Yubikey and link again the account.

Seems like this problem is not present in Mojave and Catalina. How is possible that Safari works well with the Yubikey in High Sierra but Mail can't "communicate" well with it to read the key when logging?

Anyone was able to get this working? No other way to sync it since Advanced Program close session in all devices and don't let use other method as codes or Authenticator to logging...