Caused by: java.lang.NullPointerException: Location is required

将
Parent root = FXMLLoader.load(getClass().getResource("xml/MainUI.fxml"));
改为：
 Parent root = FXMLLoader.load(getClass().getClassLoader().getResource("xml/MainUI.fxml"));

 

转载于:https://www.cnblogs.com/xiaojf/p/11060023.html