The goal of providing initUDP was to let developers know if UDP is supported on their network or not. Sadly not all networks have support for UDP. The above error means that your network does not support UDP.
The issue is caused by NAT. On some networks when you send a message through UDP, network does not store the port of sending client. So when response comes back from server, the network does not know where it should give back response.
I recommend you to use TCP as a fallback technique. Whenever you are not having UDP connectivity, use TCP.