FULL PRODUCT VERSION :
I tested the following code using the JDK 1.8.0_91, the JDK 1.8.0_111 and the actual JDK 1.8.0_112.

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 10 [Version 10.0.14393]
Microsoft Windows 8 [Version 6.3.9600]

EXTRA RELEVANT SYSTEM CONFIGURATION :
I use IntelliJ IDEA IDE.

A DESCRIPTION OF THE PROBLEM :
Please try the following **FXML view** with the corresponding **controller**. The source code demonstrates that **SplitPane** stay hidden after change its **visible property** (set true value).

The **SplitPane** appears after resizing the window.

I tested using the **FlowPane** instead the **SplitPane** and the **FlowPane** works fine.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Please try source code filled in **Source code for an executable test case**.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The SplitPane is immediately visible.
ACTUAL -
The SplitPane is not immediately visible.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No error message nor crash.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
// === sample.fxml ====================================================
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.SplitPane?>
<?import javafx.scene.text.Text?>

<AnchorPane xmlns:fx="http://javafx.com/fxml"
            fx:controller="sample.Controller">
    <Button fx:id="button"
            alignment="CENTER"
            onMouseClicked="#buttonClicked">
        Make split pane visible
    </Button>
    <SplitPane fx:id="splitPane"
               AnchorPane.topAnchor="0.0"
               AnchorPane.rightAnchor="0.0"
               AnchorPane.bottomAnchor="0.0"
               AnchorPane.leftAnchor="0.0"
               visible="false">
        <items>
            <Text>Left content</Text>
            <Text>Right content</Text>
        </items>
    </SplitPane>
</AnchorPane>

// === Controller.java ====================================================
package sample;

import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.SplitPane;

public class Controller {
    @FXML
    private Button button;
    @FXML
    private SplitPane splitPane;

    @FXML
    private void buttonClicked() {
        button.setVisible(false);
        splitPane.setVisible(true);
    }
}

// === Main.java ====================================================
package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }


    public static void main(String[] args) {
        launch(args);
    }
}
---------- END SOURCE ----------