Try to block FB=Your connection is not private, cannot proceed

Hello vedranOP,

Your issue is addressed here:

https://forum.fortinet.com/tm.aspx?m=147802&tree=true

>>Per the documentation I've read, that "should" only be necessary if you are doing deep packet inspection, which I am not.   This is correct. You do not need to import the certificate into all clients if you are using only certificate-inspection. If that is what you did and you still get a page error, that means the FortiGate is trying to forward the "replacement-message" to the browser indicating that the page is blocked. "edmunds.com" is classified as Personal Vehicles. Do you have that category set to Block in the Web Filter?   You can disable the "replacement-message" on the webfilter if you are running in proxy mode. That way, blocked pages will not attempt to print a message and instead will return an SSL reset packet.

http://cookbook.fortinet.com/preventing-certificate-warnings/

If you want to import the SSL Certificate, the link above will show you how to do it. Otherwise, you can disable the replacement message to prevent the warning.

HoMing

Hello VedranOP,

You will need to download the cert you are using for ssl inspection on the Fortigate. In your case its the default "Fortinet_CS_SSLProxy" cert. Once you have this you can ether deploy it with a GPO of your domain to PC's or manually install it into the PC's cert center. You need to put it into two locations. Trusted Publishers and Trusted Root Certification Authorities.