I get that message constantly, weekly! Not a day/week goes by that I don't get that message.
I thought it had to do w/ my old PC and outdated Windows.
I use Firefox.
I just keep trying and eventually it works.
I also get a huge page that says "SECURE SYSTEM FAILURE". Please contact us so we can help deter bogus sites."
Again, I just thought it was because my computer is old.