Google Earth Engine - Error downloading cloudfree Sentinel image

I got the following error message after trying to import cloud-free Sentinel-2 imagery for a polygon area covering the entire Tiwi Islands, Australia.

true-colour image: Layer error: internal error

// Filter to only include images intersecting Tiwi.

var polygon = ee.Geometry.Polygon({
  coords: [[
[129.90415998438357,-12.027354108834277], [131.63999982813357,-12.027354108834277],
[131.63999982813357,-11.101721188177093], [129.90415998438357,-11.101721188177093], 
[129.90415998438357,-12.027354108834277]]],

  geodesic: false
});

//  Define the image collection we are working with by writing this command
    var image = ee.Image(sent2

    // filter to get only images in the date range we are interested in
    .filterDate("2018-09-01", "2018-11-30")

    // sort the collection by a metadata property, in our case cloud cover is a very useful one

    .sort("CLOUD_COVERAGE_ASSESSMENT")

    // select the first image out of this collection - i.e. the most cloud free image in the date range
    .first());

    // print the image to the console.
    print("A Sentinel-2 scene:", image);

    // Define visualization parameters in a JavaScript dictionary for true colour rendering. Bands 4,3 and 2 needed for RGB.
    var trueColour = {

        bands: ["B4", "B3", "B2"],
        min: 0,
        max: 3000
        };

  // Add the image to the map, using the visualization parameters.
  Map.addLayer(image, trueColour, "true-colour image");