Cisco ISE - err cert authority invalid

[Orkhan Hajizada]

Hello ! I have installed and configured Cisco ISE 3.1. Guest user connects to ssid and gets it's credentials for access to internet. Everything is ok here. But when user attempts to type any site in the browser it says "err cert authority invalid". I tried to generate some certificate to fix this problem, but unsuccessfully. Can anyone tell me where and which type of certificate I should generate?

P.S Guest users connect to ssid with their own mobile phones.

[Konstantinos9]

Hello,

This seems to be an issue with an upstream device doing HTTPS inspection (Secure Web Appliance, Umbrella, Secure Firewall). Can you please confirm if there are any of these devices upstream?

If it's  a Secure Web Appliance (WSA), you may need to ensure that the certificate for HTTPS inspection is trusted by the endpoints (if it's self signed) or signed by your internal CA authority.

Let me know if this is helpful.