On self registration in Moodle,
You first get an Error about Authentication.
Then when you try to login the registered user, what welcomes you is a disappointing message about confirming the registred user through a link sent to an email that REALLY NEVER is received.
This is more so confusing when developing on a local host Serve.
PLEASE DONT PANIC,
This is what you need to do, for testing purposes.
1. log in to your administration dashboard.
2.Scroll down to >Site Administration > Users > Accounts > Browse List Of Users.
3.Identify the new user and chose to Resend Email or Confirm
4. Good to Go and hope i solved that Headache you were facing.