LibGDX JSON error: JSON standard does not allow identifiers

Question

I copied and pasted a uiskin.json file to use for Scene2D UI, but for some reason my code is still crashing. Here is the uiskin.json file that's giving me the error: JSON standard does not allow identifiers. This is stored in my asset folder along with the default.fnt, uiskin.atlas, and uiskin.png

{
  com.badlogic.gdx.graphics.g2d.BitmapFont: { default-font: { file: default.fnt } },
  com.badlogic.gdx.graphics.Color: {
  green: { a: 1, b: 0, g: 1, r: 0 },
  white: { a: 1, b: 1, g: 1, r: 1 },
  red: { a: 1, b: 0, g: 0, r: 1 },
  black: { a: 1, b: 0, g: 0, r: 0 },
},
  com.badlogic.gdx.scenes.scene2d.ui.Skin$TintedDrawable: {
  dialogDim: { name: white, color: { r: 0, g: 0, b: 0, a: 0.45 } },
},
  com.badlogic.gdx.scenes.scene2d.ui.Button$ButtonStyle: {
  default: { down: default-round-down, up: default-round },
  toggle: { down: default-round-down, checked: default-round-down, up: default-round }
},
  com.badlogic.gdx.scenes.scene2d.ui.TextButton$TextButtonStyle: {
  default: { down: default-round-down, up: default-round, font: default-font, fontColor: white },
  toggle: { down: default-round-down, up: default-round, checked: default-round-down, font: default-font, fontColor: white, downFontColor: red }
},
  com.badlogic.gdx.scenes.scene2d.ui.ScrollPane$ScrollPaneStyle: {
  default: { vScroll: default-scroll, hScrollKnob: default-round-large, background: default-rect, hScroll: default-scroll, vScrollKnob: default-round-large }
},
  com.badlogic.gdx.scenes.scene2d.ui.SelectBox$SelectBoxStyle: {
  default: {
    font: default-font, fontColor: white, background: default-select,
    scrollStyle: default,
    listStyle: { font: default-font, selection: default-select-selection }
  }
},
  com.badlogic.gdx.scenes.scene2d.ui.SplitPane$SplitPaneStyle: {
  default-vertical: { handle: default-splitpane-vertical },
  default-horizontal: { handle: default-splitpane }
},
  com.badlogic.gdx.scenes.scene2d.ui.Window$WindowStyle: {
  default: { titleFont: default-font, background: default-window, titleFontColor: white },
  dialog: { titleFont: default-font, background: default-window, titleFontColor: white, stageBackground: dialogDim }
},
  com.badlogic.gdx.scenes.scene2d.ui.ProgressBar$ProgressBarStyle: {
  default-horizontal: { background: default-slider, knob: default-slider-knob },
  default-vertical: { background: default-slider, knob: default-round-large }
},
  com.badlogic.gdx.scenes.scene2d.ui.Slider$SliderStyle: {
  default-horizontal: { background: default-slider, knob: default-slider-knob },
  default-vertical: { background: default-slider, knob: default-round-large }
},
  com.badlogic.gdx.scenes.scene2d.ui.Label$LabelStyle: {
  default: { font: default-font, fontColor: white }
},
  com.badlogic.gdx.scenes.scene2d.ui.TextField$TextFieldStyle: {
  default: { selection: selection, background: textfield, font: default-font, fontColor: white, cursor: cursor }
},
  com.badlogic.gdx.scenes.scene2d.ui.CheckBox$CheckBoxStyle: {
  default: { checkboxOn: check-on, checkboxOff: check-off, font: default-font, fontColor: white }
},
  com.badlogic.gdx.scenes.scene2d.ui.List$ListStyle: {
  default: { fontColorUnselected: white, selection: selection, fontColorSelected: white, font: default-font }
},
  com.badlogic.gdx.scenes.scene2d.ui.Touchpad$TouchpadStyle: {
  default: { background: default-pane, knob: default-round-large }
},
  com.badlogic.gdx.scenes.scene2d.ui.Tree$TreeStyle: {
  default: { minus: tree-minus, plus: tree-plus, selection: default-select-selection }
},
  com.badlogic.gdx.scenes.scene2d.ui.Tooltip$TooltipStyle: {
  default: {
    label: { font: default-font, fontColor: white },
    background: default-pane
  }
},
}

Also, this is the Java code that I have so far. Just a simple add button for reference if anyone need.

public class MyGdxGame extends ApplicationAdapter {
    private Skin skin;
    private TextField username, password;
    private Stage stage;

    @Override
    public void create () {
        skin = new Skin(Gdx.files.internal("uiskin.json"));
        stage = new Stage(new ScreenViewport());

        final TextButton button = new TextButton("Click Me", skin, "default");
        button.setWidth(200);
        button.setHeight(50);

        stage.addActor(button);
        Gdx.input.setInputProcessor(stage);
    }

    @Override
    public void render () {
        Gdx.gl.glClearColor(0, 0, 1, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        stage.act(Gdx.graphics.getDeltaTime());
        stage.draw();
    }
}

Answer 1

Tooltip is a new feature from libgdx it only exists on the nightly build so you don't have it you probably copied that from the github from libgdx and you can check here that it was added 9 days ago. I checked in my recently installed libgdx and tooltip isn't there, if you try to import it.

Basically remove:

com.badlogic.gdx.scenes.scene2d.ui.Tooltip$TooltipStyle: {
  default: {
    label: { font: default-font, fontColor: white },
    background: default-pane
  }
},