When setting up Myriad Playout Security Groups (or when assigning permissions directly to each User) you need to assign a "User Role" to users that are allowed to broadcast live using Broadcast Radio Live.
Until you set these permissions, the user will not be able to connect to the Live Room:
The roles currently available are:
Announcers are able to connect, but can’t put their own microphone live. Their microphone can be controlled by any Producers connected to the room.
Presenters have permission to make their own mic live, but cannot control the microphones of other connected users.
Producers have full access to the BR Live mixer, can turn any microphone on/off, and change advanced room settings as well change the routing/mix on any of the microphones.