The link you posted for the Intuit signin above is not the secure version of the TurboTax URL, but it's possible that the http link should normally redirect to the https (secure) version when it's working. Maybe it's not redirecting properly. In any case, try placing an "s", i.e., using https instead of http and see if that makes a difference when you go directly to the secure URL.
NOTE: You may wish to clear your browser Internet cache before trying again, or it may remember your previous results.
If using the direct https link didn't help, try using Private Browsing mode (aka Incognito Mode) to see if the error recurs.
If you still get an error message after all that, do you have a different browser to try?
