Destinations registered for SSE services are unreachable when used in OSGi (Karaf, blueprint).
The problem seems to be that SseHttpTransportFactory creates it's own private DestinationRegistry where it registers it's destinations.
While at the same time handling of incoming requests queries an instance of DestinationRegistry created in HTTPTransportActivator (bundle activator of http transport).
The same failure mode in websocket transport is averted by a workaround in WebSocketDestinationFactory HERE starting with:
// REVISIT other way of getting the registry of http so that the plain cxf servlet finds the