Openfire offers functionality to suppress the broadcast of occupants that have a certain role. The implementation is based on the definition of that role that should be present in the presence stanza to be broadcast.
When the presence stanza that is being processed does, for some reason, not include this role, the implementation fails. The exception below is logged by Openfire 4.6.1-SNAPSHOT.
It should be a lot safer to base the broadcast/do not broadcast decision based on the role that is assigned to the user.