UM 4.16 and 5.0RC8 both do not work for me.
Was running 5.0RC8 for a few days, then suddenly it started not authenticating logins.
Just says "PPPoE connection from was already active - closing previous one".
An then in PPP sessions pppoe-0 appears, in stead of customer name, and it just drops.
Sometimes it helps deleting customer form UM and adding new customer with same login/password.