This problem has occurred to me and lots of other people as well because I hear about it all the time. It seems like web browsers work one day and then not the next. Somesites work. Other sites don't. What's going on here?
Ken I agree that this has become a very annoying situation. The first thing I would try is when you have a problem with a website I always try to use a different browser. If your default is Internet Explorer and the site just doesn't seem to work copy the URL and open Chrome or Firefox and paste the URL. Do the same if you have a Mac, Try Chrome instead of Safari.
If that doesn'y solve the problem, it is most likely the browser extension. The browser extensions are additions to browsers to enhance the browser. Sometimes these extensions or Add-On's just don't work correctly.
You can disable or remove the extension by going into the settings of your browser. This is different for every browser so do a search on your favorite search engine for "How to disable extensions for Internet Explorer, or Safari". Follow the instruction to disable extensions.
This may fix the problems and in many cases it will speed up your browser activity.