Re: [Boost-users] [Boost.asio] Second multicast async_send_to returns 10009

Igor R writes:

error 10009 probably means that the handle of your socket is invalid. Maybe, the socket object is destroyed? Put a breakpoint at MulticastServer destructor and look when you come there and why...

That was it. Changed it from a local variable on the stack in the thread function to an instance variable on the class and it started working. Odd that it would get destructed when the thread function was blocking on io_service.run(). Thanks for the help.