fix(MulticastClient): ignore receive error. Fixes #79

src/MulticastClient.cs

@@ -161,6 +161,8 @@ await sender.Value.SendAsync(
 
         void Listen(UdpClient receiver)
         {
+            // ReceiveAsync does not support cancellation.  So the receiver is disposed
+            // to stop it. See https://github.com/dotnet/corefx/issues/9848
             Task.Run(async () =>
             {
                 try
@@ -173,6 +175,10 @@ void Listen(UdpClient receiver)
 
                     await task.ConfigureAwait(false);
                 }
+                catch (NullReferenceException)
+                {
+                    return;
+                }
                 catch (ObjectDisposedException)
                 {
                     return;
@@ -204,15 +210,29 @@ protected virtual void Dispose(bool disposing)
 
                     foreach (var receiver in receivers)
                     {
-                        receiver.Dispose();
+                        try
+                        {
+                            receiver.Dispose();
+                        }
+                        catch
+                        {
+                            // eat it.
+                        }
                     }
                     receivers.Clear();
 
                     foreach (var address in senders.Keys)
                     {
                         if (senders.TryRemove(address, out var sender))
                         {
-                            sender.Dispose();
+                            try
+                            {
+                                sender.Dispose();
+                            }
+                            catch
+                            {
+                                // eat it.
+                            }
                         }
                     }
                     senders.Clear();