Prompt not detected - upload failed. Trying to recover...

try not adding save() to the end of what you upload, then do it manually.

If you do that the following should work fine, and is the best way of working:

let WIZnet = require("WIZnet");
E.on('init', function () {
  SPI2.setup({ mosi:B15, miso:B14, sck:B13 });
  let eth = WIZnet.connect(SPI2, B10);
  eth.setIP();
});