UDP broadcast not sent and blocks board (N3E)


I want to broadcast UDP-packets on a Netduino3 Ethernet (firmware:
Looking around the internet and the forum i found information about it and it seems to work.
When i try to broadcast UDP the board blocks when sending.

here the code i use:

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Parse(""), 10000);

byte[] data = Encoding.UTF8.GetBytes("hello, world!");

// netduino hangs here:
socket.SendTo(data, ipEndPoint);

i also tried with (same result):

socket.SendTo(data, data.Length, SocketFlags.Broadcast, ipEndPoint);

what’s wrong?
how would i broadcast UDP?