No new serial port detected

I have just installed XOD IDE version 0.37.3. I try first to implement a very simple sketch to put a led on and of on an Arduino Micro. Every time the serial session starts but nothing happens when I try to upload the sketch. I get every time: " Waiting for upload port…" and a few seconds after the message: “No new serial port detected” and the Upload fails ?? What can I do to fix these error. ??