I had that a week or so ago, along with a lot of malvertising page redirects (Loads the intended page, then after 2-3 seconds diverts you to a phishing site) - Google/Chrome blocked the entire domain for me several times.
I changed to Firefox to view the forum, and both problems were solved, even whilst issues with Chrome persisted.
Chrome viewing is now back to normal for me with no issues.
An overnight reboot seems to have resolved the problem for now. I am using Chrome. If it happens again, I will try a different browser to see if it is specific to Chrome for me too.