Firefox not correctly loading/interacting with some websites
I have used Firefox on both Windows and Mac systems for many years with no problem. Recently I have experienced several. In one case a website that i have logged onto for at lest 10 years was displayed incorrectly and would not accept my password. It ran perfectly in Safari. This problem was cured by clearing the cache and cookies. Currently, I cannot load comments to the "comments" sections of Wall Street Journal articles - a message tells me that I am trying to load "malformed content" Again, the site functions correctly in Safari. In contrast however, clearing cache, cookies and history does not restore functionality in Firefox.
What has changed?