Hummingbird performance test didn't return any results.

Hummingbird performance test didn't return any results. Tried from hub clearing server cache but no luck. I am getting the following error:
"The performance test didn't return any results. This probably means you're on a local website (which we can't scan) or something went wrong trying to access WPMU DEV. Try again and if this error continues to appear please open a ticket with our support heroes"