New interpreter error: FIFO_FULL?

I ran codes in STM32F4DISCOVERY board.

I used MQTT module， when I didn't access board by IDE, just open the power, MQTT failed, datas couldn't send to server, but the board do get ip and access into network fine. Then I accessed into IDE, showed log like this. When I always accessed IDE, it's okay all the time.

New interpreter error: FIFO_FULL

What's this means? How to avoid this error without IDE?

My codes

E.on('init', function () {


  setTimeout(() => {
   eth = WIZnet.connect(SPI2, B12);
   eth.setIP();
   console.log(eth.getIP());
  },2000);
  
 setTimeout(() => {
    mqtt = mqttLib.connect({
      host: serip,
      username: "admin",
      password: "admin",
      client_id: "33333333333"
    });
    mqtt.on('connected', function () {
      console.log("connect to mqtt success");
      rhb();
    });
  }, 8 * 1000);
});
function rhb() {
  console.log("enter a heartbeat runner......");
  let hber = setInterval(() => {
    if (mqtt) {
      mqtt.publish(hbTopic, JSON.stringify({
        sn: "22222222222"
      }));
    }
  }, 1000);
}
save();

First guess is either
https://www.espruino.com/Troubleshooting#i-typed-save-but-espruino-won-t-work-or-stops-working-quickly-when-powered-from-a-computer-it-only-works-from-a-usb-power-supply-battery-or-the-computer-when-the-web-ide-is-running-
or
https://www.espruino.com/Troubleshooting#espruino-works-when-connected-to-a-computer-but-stops-when-powered-from-something-else

Oh, the first one is right. I unplug the USB cable, all going well. Thank you!