Fortigate web site block page not appearing

[vishal]

Hello All, I'm using fortigate 50D and configure web filter policy to block some unwanted sites . Basically I'm facing an issue where my site got blocked but instead of Fortigate Block page it show's "This site can't be reached". Please help me is it I miss something in configuration

[mzainuddinahm]

Basically, the main reason why you are not able see the block page is due to flow-based inspection mode of the firewall policy.
In order to be able to see the replacement block messages for untrusted blocked certificate, it is necessary to set firewall policy to proxy based mode.