Program: 30319
Project: 30319
Buggy source:
@Override public void create(){
  skin=new Skin(Gdx.files.internal(SKIN));
  EditorLogger.setDebug();
  EditorLogger.debug("String_Node_Str");
  Ctx.project=new Project();
  Ctx.msg=new Message(skin);
  Ctx.assetManager=new EditorAssetManager();
  scnEditor=new ScnEditor(skin);
  skin.getFont("String_Node_Str").getData().markupEnabled=true;
  stage=new Stage(new ScreenViewport());
  Gdx.input.setInputProcessor(stage);
  ScenePanel scenePanel=new ScenePanel(skin);
  ActorPanel actorPanel=new ActorPanel(skin);
  Table rightPanel=new Table();
  rightPanel.top().left();
  rightPanel.add(actorPanel).expand().fill();
  SplitPane splitPaneRight=new SplitPane(scnEditor,rightPanel,false,skin);
  ProjectPanel projectPanel=new ProjectPanel(skin);
  Image img=new Image(Ctx.assetManager.getIcon("String_Node_Str"));
  img.setScaling(Scaling.none);
  img.setAlign(Align.left);
  Table leftPanel=new Table();
  leftPanel.top().left().padLeft(10);
  leftPanel.add(img).expand().fill().padBottom(20).padTop(20).padLeft(20);
  leftPanel.row();
  leftPanel.add(new ProjectToolbar(skin)).expandX().fill();
  leftPanel.row();
  leftPanel.add(projectPanel).expand().fill();
  leftPanel.row();
  leftPanel.add(scenePanel).expand().fill();
  SplitPane splitPaneLeft=new SplitPane(leftPanel,splitPaneRight,false,skin);
  splitPaneLeft.setFillParent(true);
  splitPaneLeft.setSplitAmount(0.3f);
  stage.addActor(splitPaneLeft);
  String lastProject=Ctx.project.getEditorConfig().getProperty(Project.LAST_PROJECT_PROP,"String_Node_Str");
  if (!lastProject.isEmpty() && new File(lastProject).exists()) {
    try {
      EditorLogger.debug("String_Node_Str" + lastProject);
      Ctx.project.loadProject(new File(lastProject));
    }
 catch (    Exception e) {
      EditorLogger.debug("String_Node_Str" + e.getMessage());
      Ctx.project.closeProject();
      e.printStackTrace();
    }
  }
  stage.setScrollFocus(scnEditor.getScnWidget());
  stage.setKeyboardFocus(scnEditor.getScnWidget());
  TooltipManager.getInstance().instant();
  TooltipManager.getInstance().enabled=false;
}

Fixed version (ground truth):
@Override public void create(){
  skin=new Skin(Gdx.files.internal(SKIN));
  EditorLogger.setDebug();
  EditorLogger.debug("String_Node_Str");
  Ctx.project=new Project();
  Ctx.msg=new Message(skin);
  Ctx.assetManager=new EditorAssetManager();
  scnEditor=new ScnEditor(skin);
  skin.getFont("String_Node_Str").getData().markupEnabled=true;
  stage=new Stage(new ScreenViewport());
  Gdx.input.setInputProcessor(stage);
  ScenePanel scenePanel=new ScenePanel(skin);
  ActorPanel actorPanel=new ActorPanel(skin);
  Table rightPanel=new Table();
  rightPanel.top().left();
  rightPanel.add(actorPanel).expand().fill();
  SplitPane splitPaneRight=new SplitPane(scnEditor,rightPanel,false,skin);
  ProjectPanel projectPanel=new ProjectPanel(skin);
  Image img=new Image(Ctx.assetManager.getIcon("String_Node_Str"));
  img.setScaling(Scaling.none);
  img.setAlign(Align.left);
  Table leftPanel=new Table();
  leftPanel.top().left().padLeft(10);
  leftPanel.add(img).expand().fill().padBottom(20).padTop(20).padLeft(20);
  leftPanel.row();
  leftPanel.add(new ProjectToolbar(skin)).expandX().fill();
  leftPanel.row();
  leftPanel.add(projectPanel).expand().fill();
  leftPanel.row();
  leftPanel.add(scenePanel).expand().fill();
  SplitPane splitPaneLeft=new SplitPane(leftPanel,splitPaneRight,false,skin);
  splitPaneLeft.setFillParent(true);
  splitPaneLeft.setSplitAmount(0.3f);
  stage.addActor(splitPaneLeft);
  String lastProject=Ctx.project.getEditorConfig().getProperty(Project.LAST_PROJECT_PROP,"String_Node_Str");
  if (!lastProject.isEmpty() && new File(lastProject).exists()) {
    try {
      EditorLogger.debug("String_Node_Str" + lastProject);
      Ctx.project.loadProject(new File(lastProject));
    }
 catch (    Exception e) {
      EditorLogger.debug("String_Node_Str" + e.getMessage());
      Ctx.project.closeProject();
      e.printStackTrace();
    }
  }
  stage.setScrollFocus(scnEditor.getScnWidget());
  stage.setKeyboardFocus(scnEditor.getScnWidget());
  TooltipManager.getInstance().instant();
}