1. I installed WPMU DEV. 2. I go filled form (as membership

1. I installed WPMU DEV.
2. I go filled form (as membership profile)
First Name = peterstolypin
Your email = p.eterstolypin@gmail.com
Choose your password = 555666
I press "Get your API key" and got error:
" This email is invalid or in use already. Please enter a valid email."
3. Then I clicked on the button "Already a member? Click here.", but nothing happened.