When I access this site from work, I get a McAfee warning that "We cannot confirm if this site is safe". I don't know what McAfee wants, but perhaps you could reach out to them to see what they consider a "safe" site?
The only indication I've seen along those lines is a complaint from Windows that the site's security certificate is bad. Norton may have other reasons, but they'll have to explain them. What browser are you using? I just accessed the URL in your post with no problem using Firefox on Windows 10.