Membership2 cannot find "Existing WordPress users"

I have WordPress users (all admins), and I have Membership Pro 2

I want to add my WordPress users to Membership Pro 2. When I go to “Add Member” and try to select an existing wordpress user, it can’t find any users.

I tried to search my name, email, nice name. Nothing comes up.

Screencast of the situation: http://screencast.com/t/krtrfQdl60R