Caused by: java.lang.NumberFormatException: empty String
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:994)
        at java.lang.Double.valueOf(Double.java:475)
        at com.sun.javafx.fxml.BeanAdapter.coerce(BeanAdapter.java:646)
        at com.sun.javafx.fxml.BeanAdapter.coerce(BeanAdapter.java:667)
        at com.sun.javafx.fxml.BeanAdapter.put(BeanAdapter.java:386)
        at com.sun.javafx.fxml.BeanAdapter.put(BeanAdapter.java:45)
        at javafx.fxml.FXMLLoader$Element.applyProperty(FXMLLoader.java:261)
        at javafx.fxml.FXMLLoader$Element.processPropertyAttribute(FXMLLoader.java:255)
        at javafx.fxml.FXMLLoader$Element.processEndElement(FXMLLoader.java:125)
        at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:381)
        at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:1595)
        at javafx.fxml.FXMLLoader.load(FXMLLoader.java:1415)
        at com.oracle.javafx.authoring.persist.FXMLDocument.load(FXMLDocument.java:413)