cannot set renderer on openlayers 3 - openlayers-3

Question

According to a book I am reading about Openlayers 3 , all I have to do, to reset the renderer is to do this in the Map initialization
renderer: 'dom'
so my code is
var map = new ol.Map({
target: 'map',
layers: [layer],
renderer: 'dom',
view: view,
});
When I load the page, the console gives no errors, but the map does not load at all. I use Openlayers 3.9.0. What is going wrong here?
Thanks
EDIT
This is all the openlayers code
var layer = new ol.layer.Tile({
source: new ol.source.OSM()
});
var kbz = new ol.interaction.KeyboardZoom();
var dr = new ol.interaction.DragRotateAndZoom();
var control = new ol.control.FullScreen();
var center = ol.proj.transform([-1.812, 52.443], 'EPSG:4326', 'EPSG:3857');
var we = new ol.Overlay({
position: center,
element: document.getElementById('we')
});
var view = new ol.View({
center: center,
zoom: 6
});
var map = new ol.Map({
target: 'map',
layers: [layer],
renderer: 'dom',
view: view
});
map.addInteraction(kbz);
map.addInteraction(dr);
map.addControl(control);
map.addOverlay(we);

Answer 1

You have to set the size of the map target element, when using the dom renderer.
Canvas elements, which are used by the default renderer, has a default height of 150px, while normal divs don't have a default height. Setting the height of the target should make you map appear:
#map {
height: 200px;
}