@kathyldb -- if you can see the list of those 30 "blocked" sites, can you click to select one of them, and then click to "unblock" it?
What anti-virus product are you using that has a "black-list"?
Note that "trusted" web-sites have received a "certificate" that their site is trusted. Each certificate has an expiry-date. So, it is possible that a web-site's certificate has expired, and thus the site is no longer trusted.
Please name a few sites that are on that list, so that I can check their certificates.