Send unreliable messages in group activities

Hello

Has anyone tried to send unreliable messages in first beta?

I have a bad access crash every time I try:

(lldb) thread backtrace

* thread #28, queue = 'com.apple.root.user-initiated-qos.cooperative', stop reason = EXC_BAD_ACCESS (code=1, address=0x22)

  * frame #0: 0x00000001033aa3b4 libdispatch.dylib`_dispatch_root_queue_drain + 208

    frame #1: 0x00000001033aae6c libdispatch.dylib`_dispatch_worker_thread2 + 196

    frame #2: 0x00000001f9b8d06c libsystem_pthread.dylib`_pthread_wqthread + 228

I don't know if I do something wrong or if someone else experiences the same issue.

Thanks,

Gil