FULL PRODUCT VERSION :
java version "9"
Java(TM) SE Runtime Environment (build 9+180)
Java HotSpot(TM) 64-Bit Server VM (build 9+180, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows 8.1 (x64)
Linux Mint 18 "Sarah" - Cinnamon (64-bit)
MacOSX (Sierra)

A DESCRIPTION OF THE PROBLEM :
According to this page http://openjdk.java.net/jeps/275 the javapackager should now have the --module and --module-path switches. However, I get a nullpointer when trying to build a simple HelloWorld-module with the javapackager. The very same error occurs on MacOSX and Linux as well as Windows. A native runtime image can be produced with the jlink command but fails with the javapackager.

REGRESSION.  Last worked in version 9

ADDITIONAL REGRESSION INFORMATION: 
java version "9"
Java(TM) SE Runtime Environment (build 9+180)
Java HotSpot(TM) 64-Bit Server VM (build 9+180, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Create a simple com.example.Main-class. Create a module-info.java with the content i.e.

module helloworld.module {
    exports com.example;
}

2. Create a jar with the compiled class and a META-INF/MANIFEST.MF folder/file with the following:
Manifest-Version: 1.0
Main-Class: com.example.Main

3. Run the javapackager with the jar-file in module-path:
>javapackager -deploy -v -outdir release -name HelloWorldJava9 -native image --module-path "HelloWorldJava9.jar;C:\Program Files\Java\jdk-9\jmods" --module helloworld.module/com.example.Main


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected result is that a native runtime image is created from the module.
ACTUAL -
C:\HelloWorldJava9\target>javapackager -deploy -v -outdir release -name HelloWorldJava9 -native image --module-path "HelloWorldJava9.jar;C:\Program Files\Java\jdk-9\jmods" --module helloworld.module/com.example.Main
Running [C:\Program Files\Java\jdk-9\bin\java.exe, -version]
Creating app bundle: HelloWorldJava9 in C:\HelloWorldJava9\target\release
Exception: java.lang.NullPointerException
Exception in thread "main" com.sun.javafx.tools.packager.PackagerException: Error: Bundler "Windows Application Image" (windows.app) failed to produce a bundle.
        at jdk.packager/com.sun.javafx.tools.packager.PackagerLib.generateNativeBundles(PackagerLib.java:374)
        at jdk.packager/com.sun.javafx.tools.packager.PackagerLib.generateDeploymentPackages(PackagerLib.java:348)
        at jdk.packager/com.sun.javafx.tools.packager.Main.main(Main.java:496)

ERROR MESSAGES/STACK TRACES THAT OCCUR :
same with the --add-modules switch:

C:\HelloWorldJava9\target>javapackager -deploy -v -outdir release -name HelloWorldJava9 -native image --module-path "HelloWorldJava9.jar;C:\Program Files\Java\jdk-9\jmods" --add-modules helloworld.module --module helloworld.module/com.example.Main
Running [C:\Program Files\Java\jdk-9\bin\java.exe, -version]
Creating app bundle: HelloWorldJava9 in C:\HelloWorldJava9\target\release
Exception: java.lang.NullPointerException
Exception in thread "main" com.sun.javafx.tools.packager.PackagerException: Error: Bundler "Windows Application Image" (windows.app) failed to produce a bundle.
        at jdk.packager/com.sun.javafx.tools.packager.PackagerLib.generateNativeBundles(PackagerLib.java:374)
        at jdk.packager/com.sun.javafx.tools.packager.PackagerLib.generateDeploymentPackages(PackagerLib.java:348)
        at jdk.packager/com.sun.javafx.tools.packager.Main.main(Main.java:496)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
Main.java:

package com.example;

public class Main {

    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

module-info.java:

module helloworld.module {
    exports com.example;
}

META-INF/MANIFEST.MF:

Manifest-Version: 1.0
Main-Class: com.example.Main
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
I can use jlink for now but later on I would like to package the app in exe/dmg/deb/rpm using the javapackager.

This works:

C:\HelloWorldJava9\target>jlink --output release\HelloWorldJava9 --compress=2 --module-path "HelloWorldJava9.jar;C:\Program Files\Java\jdk-9\jmods" --add-modules helloworld.module