Ok. Here's the diagnosis. Any attempt to create the account returns a "Fatal exception of type MWException". The account and SUL get created but, email and password get left out. Essentially, the user can't login with the password set or provided by email. Nor can they confirm email and use it to reset the password. This essentially leaves a corrupted, unusable account. Replicating it is easy, just try to create an account.
Version: unspecified
Severity: critical
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=49604