Customer can't create Pro Site


My Customer can't create Pro Site:

elisefrederik@icloud.com12:45 PM
Hi, I get the message that my username and emailaddress are used already. Not sure how to reserve a site. I would like to use the naame for my domaine.

I have looked in the User Activation key to see if I can free things up but I don't see that this user has tried to register.

The only thing I can think of is that I saw that the user made a booking via Events Manager on my subsite:

How do we fix this and why did it happen?

Support access is granted.