Hummingbird can't run performance report on our website

Installed the WPMU dashboard, also installed Hummingbird, but when I tried to run a test, I received the following error message: "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"

Can you help?
Thanks!
Hollis