I had this problem on two desktops, one worked, the other I could only get one web site out of 100's. I went round and round like all of the rest of you, following solutions that worked for other people but not for me. I checked both computers for their security and they were the same. The bad computer wouldn't work on IE nor chrome.
Then I noticed an error on the chrome page, not in sync. After finally getting it in sync, everything works. I'm not saying this is a cure all but it works on both browsers now.