Program: 45606
Project: 45606
Buggy source:
/** 
 * Load model from file
 * @param origFile
 */
ImportedModel loadModel(ImportSettings settings) throws IOException {
  Node rootBG=new Node();
  URL url=settings.getModelURL();
  if (url.getProtocol().equalsIgnoreCase("String_Node_Str")) {
    lastModelDir=new File(url.getFile()).getParentFile();
  }
  Node modelBG=null;
  ModelLoader modelLoader=LoaderManager.getLoaderManager().getLoader(url);
  LOGGER.fine("String_Node_Str" + modelLoader);
  if (modelLoader == null) {
    String urlString=url.toExternalForm();
    String fileExtension=FileUtils.getFileExtension(urlString);
    String message=BUNDLE.getString("String_Node_Str");
    message=MessageFormat.format(message,fileExtension);
    JOptionPane.showMessageDialog(null,message);
    return null;
  }
  ImportedModel loadedModel=modelLoader.importModel(settings);
  modelBG=loadedModel.getModelBG();
  rootBG.attachChild(modelBG);
  WorldManager wm=ClientContextJME.getWorldManager();
  RenderManager renderManager=wm.getRenderManager();
  ZBufferState buf=(ZBufferState)renderManager.createRendererState(RenderState.RS_ZBUFFER);
  buf.setEnabled(true);
  buf.setFunction(ZBufferState.TestFunction.LessThanOrEqualTo);
  MaterialState matState=(MaterialState)renderManager.createRendererState(RenderState.RS_MATERIAL);
  rootBG.setRenderState(matState);
  rootBG.setRenderState(buf);
  Entity entity=new Entity(loadedModel.getWonderlandName());
  RenderComponent scene=renderManager.createRenderComponent(rootBG);
  entity.addComponent(RenderComponent.class,scene);
  entity.addComponent(TransformProcessorComponent.class,new TransformProcessorComponent(wm,modelBG,rootBG));
  wm.addEntity(entity);
  loadedModel.setEntity(entity);
  return loadedModel;
}

Fixed version (ground truth):
/** 
 * Load model from file
 * @param origFile
 */
ImportedModel loadModel(ImportSettings settings) throws IOException {
  Node rootBG=new Node();
  URL url=settings.getModelURL();
  if (url.getProtocol().equalsIgnoreCase("String_Node_Str")) {
    lastModelDir=new File(url.getFile()).getParentFile();
  }
  Node modelBG=null;
  ModelLoader modelLoader=LoaderManager.getLoaderManager().getLoader(url);
  LOGGER.fine("String_Node_Str" + modelLoader);
  if (modelLoader == null) {
    String urlString=url.toExternalForm();
    String fileExtension=FileUtils.getFileExtension(urlString);
    String message=BUNDLE.getString("String_Node_Str");
    message=MessageFormat.format(message,fileExtension);
    JOptionPane.showMessageDialog(null,message);
    return null;
  }
  ImportedModel loadedModel=modelLoader.importModel(settings);
  modelBG=loadedModel.getModelBG();
  rootBG.attachChild(modelBG);
  WorldManager wm=ClientContextJME.getWorldManager();
  RenderManager renderManager=wm.getRenderManager();
  ZBufferState buf=(ZBufferState)renderManager.createRendererState(RenderState.RS_ZBUFFER);
  buf.setEnabled(true);
  buf.setFunction(ZBufferState.TestFunction.LessThanOrEqualTo);
  MaterialState matState=(MaterialState)renderManager.createRendererState(RenderState.RS_MATERIAL);
  rootBG.setRenderState(matState);
  rootBG.setRenderState(buf);
  Entity entity=new Entity(loadedModel.getWonderlandName());
  RenderComponent scene=renderManager.createRenderComponent(rootBG);
  entity.addComponent(RenderComponent.class,scene);
  scene.setLightingEnabled(loadedModel.getImportSettings().isLightingEnabled());
  entity.addComponent(TransformProcessorComponent.class,new TransformProcessorComponent(wm,modelBG,rootBG));
  wm.addEntity(entity);
  loadedModel.setEntity(entity);
  return loadedModel;
}