Dashbaoard plugin won't allow me to log in

The site is staging.starfishaccounting.co.uk. It is on a subdomain for a site that is already using WPMU DEV stuff. I have installed the Dashboard Plugin, and when I go to log in, I get the url with my API key, but I get this message "You do not have sufficient permissions to access this page."

I have tried logging out and in, and reinstalling the plugin. None of that has worked.