I'm using this plugin in a WP multi-site install. A user who tries to login receives "Error creating user!" That same user, in the "Test Tool" I get this:
[NOTICE] Creating user 'waterstc' with following data:
- email : email@example.com
- first name : Thomas
- last name : Waters
- display name : WATERSTC
- account suffix: @pitt.edu
- role : editor
[DEBUG] Setting local password to the used for this login.
[ERROR] Sorry, that email address is already used!
[NOTICE] - user_id :
[FATAL] Error creating user.
Error creating user!
Is the issue surrounding the multisite set up?