I too have been hit with this and many other false positives. I have found that the webshield aspect of Avast and other anti-virus program are almost always false positives. Now that might be because I haven't tried to access the truly fishy websites and therefore it just seems that 99% of sites blocked are false positives.
I added the marvel fandom wiki site as an exemption. When I did that it allowed me to open the page but then avast displays a "warning" that the site "may have damaged this computer". I am given one option to "take me out of here". It does not allow a closing of the warning, a "allow access anyway" or anything else.