First: You said "AVAST" in the title and McAffee in the subject.
As was mentioned you can white list RV.Net..
Avast however has never caused me that problem, Nor has any of the other assorted anti-virals I use, though there is one I do not think I've ever tried here.
What can happen: IN the past I have had this with SOME sites (not this one) sites are ad-supported, some times they subscribe to an ad service (this service pays them so much per visit to allow the service, often Google Ads, to put up ads on the site) Some of those ads may be links to malicious sites.
Some Anti-Viral products will then identify the site as an "Attack Site" Avast does this.. Takes a wile for the site owner to identify the offending ads, Notify the ad service, and the ad service to take action to block that advertiser.