IllegalStateException running NetBeans Modular Maven project

[jgneff]

The NetBeans Modular Maven sample project fails to run and prints the exception shown below:

$ mvn clean javafx:jlink
...
[INFO] BUILD SUCCESS
...
$ target/hellofx/bin/launcher 
Exception in Application start method
java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
	at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.RuntimeException: Exception in Application start method
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
	at java.base/java.lang.Thread.run(Thread.java:830)
Caused by: java.lang.IllegalStateException: Location is not set.
	at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2459)
	at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:2435)
	at [email protected]/org.openjfx.hellofx.App.loadFXML(App.java:32)
	at [email protected]/org.openjfx.hellofx.App.start(App.java:20)
	at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
	at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
	at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
	at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
	at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
	at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
	at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:277)
	... 1 more
Exception running application org.openjfx.hellofx.App

The same error occurs when the application is launched from the IDE or with the command mvn clean javafx:run. I'm running under the following environment:

#!/bin/bash
# Sets up the environment for building JavaFX applications
syspath=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

# JavaFX Linux SDK and JMODs
export JAVAFX_SDK=$HOME/lib/javafx-sdk-13/lib
export JAVAFX_JMODS=$HOME/lib/javafx-jmods-13

export JAVA_HOME=$HOME/opt/jdk-13.0.1
export ANT_HOME=$HOME/opt/apache-ant-1.10.7
export GRADLE_HOME=$HOME/opt/gradle-6.0-rc-1
export PATH=$GRADLE_HOME/bin:$ANT_HOME/bin:$JAVA_HOME/bin:$syspath

I will follow up shortly with a pull request that fixes the problem.