I have Comodo Internet Security on my home computer. When I try to access Airnav.com I get a page that says “Warning: Unsafe Website Blocked!” from Comodo SecureDNS. It says, “Prohibited Content: Site may contain content that is prohibited on this network”. I am (I hope) attaching an image of it.
I did a google search and tried to follow the guidance I found for setting up rules and stuff, but I’m not a computer guy and the discussions/instructions talked about stuff I don’t see on my screen.
I’m not sure what else to try, except for maybe uninstalling Comodo and then seeing if I can get to the web site. I am able to access it on my tablet and I can get to it from work (where it seems like the corporate overlords block just about everything).
I used the instructions you linked to (I have Windows 7). I would never have found the DNS setting without that guidance. I wrote down the existing DNS numbers, and then clicked the “select automatically” box. Now it works!