StayLDS forums do not use the secure, encrypted HTTPS protocol. This site uses regular, old-school HTTP. That can sometimes pop up as a warning on some browsers and/or firewalls as a security risk. That’s what it sounds like happened.
In order to run using HTTPS, the site would need to acquire one of these SSL “certificates” from a third party that issues them. In recent years, there have been some free options, but usually it costs extra money. I’m not a big expert on this, but I have used these types of certificates and setup secure sites before. It’s not terribly difficult, but would take some time and effort (and perhaps cost).