unity3d 連網 SecurityException

SecurityException: Unable to connect, as no valid crossdomain policy was found
System.Net.Sockets.Socket.Connect_internal (IntPtr sock, System.Net.SocketAddress sa, System.Int32& error, Boolean requireSocketPolicyFile)
System.Net.Sockets.Socket.Connect (System.Net.EndPoint remoteEP, Boolean requireSocketPolicy)
System.Net.Sockets.Socket.Connect (System.Net.EndPoint remoteEP)
System.Net.Sockets.UdpClient.DoConnect (System.Net.IPEndPoint endPoint)
System.Net.Sockets.UdpClient.Connect (System.Net.IPEndPoint endPoint)

System.Net.Sockets.UdpClient.Connect (System.String hostname, Int32 port)

      之前team 裡人也遇到過這個問題，後來通過複製別人的工程解決了， 這次是大家全軍覆沒，所以我就想辦法了，

一頓Google之後發現web player會報這個錯，一看頓時暈了，我工程啥時候變成web player了

菜單 File -> Buliding Settings -> PC and Mac Standalone,

然後點下面按鈕 Switch Platform 切換平台

問題解決