After several tries, here is what has worked for me and it has helped some friends. First, clear your browser cache and close your browser. Second, flush your DNS cache. Third, restart your computer. The DNS cache flush may be most important, so if you want a fast fix, try it first (after closing your browser) and see if that helps. But I suggest doing all 3 steps. Search for details of how to clear the cache of your specific browser and how to flush the DNS cache for your computer. On Windows machines, for example, the proper approach may be to run CMD as administrator (press the Windows button, search for CMD, then right click on the CMD program and select “run as administrator”) and then type “ipconfig /flushdns” (without the quotes). On my Mac, I had to run terminal and then enter “sudo dscacheutil -flushcache” (without the quotes). Check for your operating system.
But what is going on? Some article at Reddit (here and here) explore the possibility of this being some kind of practice of new capabilities related to the Great Cannon. I’m not sure. But it’s ugly and frightening that it can happen so easily. It may be that using https:// connections for added security could help prevent the problem in the future. That’s just a guess.