Hummingbird - No results

I have just installed hummingbird onto my main site to give it a test. After installing i get the 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' and the websit plugin and;
' The URL was fetched, but nothing was rendered. Ensure that the URL points to an HTML page that loads successfully in a web browser.' on the wpmudev website hub.

Any ideas as to why this could be happening? I'd love some help with this!
Thanks, Andrew