Something just doesn't look right in your server app. You are opening a single UDP connection, but reading and writing data to the same connection from within the loop. In general, UDP is one directional. One part sends, another part receives. Yet you have the server reading, then writing on the same UDP port reference wire.
I'd suggest taking a closer look again at the UDP example programs.
Be careful with your programming style. In your receiver program, you have the UDP close connection which is actually wired outside of the loop laying on top of the loop as shown by the shadows. That makes it really hard to read what is going on in the program. Also, you have numerous places where wires run backwards. The data on the wires should always flow from left to right and top to bottom. As you have it, it is difficult to tell what wires are inputs to different functions and which are outputs. Many of the structures seem duplicated and could probably be placed into subVI's.
