Unable to add new user "This userid is in use. Choose another email"
When I try to add a new admin user to my instance, I get the following message "This userid is in use. Choose another email". I confirmed the e-mail in questions is NOT currently an admin user. I thought maybe he was a lead and the system was confusing the two, so i deleted his lead record (this is sandbox so no data integrity issues) but get the same message.
Then I remembered, I think each e-mail address can only be associated with one Marketo instance. Is that true? The person I am trying to add must have access to another instance with that e-mail address.