When setting file associations for Windows, the bundling fails with NullPointerException.

build.xml:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project xmlns:fx="javafx:com.sun.javafx.tools.ant" default="fx-deploy">
    <taskdef classpath="C:\Program Files\Java\jdk1.8.0_40\\lib\ant-javafx.jar" resource="com/sun/javafx/tools/ant/antlib.xml" uri="javafx:com.sun.javafx.tools.ant"/>
    <target name="fx-deploy">
        <fx:deploy nativeBundles="exe" outdir="C:\Users\gtee\AppData\Local\Temp\2\testBundlerWorkDir3656782343067304372" outfile="test" verbose="true">
            <fx:resources>
                <fx:fileset dir="C:\Users\gtee\AppData\Local\Temp\2\testBundlerWorkDir3656782343067304372\jars" includes="testFxAppWithUtil.jar,Util.jar"/>
            </fx:resources>
            <fx:platform/>
            <fx:preferences/>
            <fx:application/>
            <fx:info>
                <fx:association description="The sample description" entension="foo bar" mimetype="application/example"/>
                <fx:association entension="mambo jumbo" icon="C:\Cygwin\home\gtee\dg\appBundlerTests-8u40\build\classes\com\oracle\appbundlers\utils\resources\icon2ico" mimetype="application/sample"/>
            </fx:info>
            <fx:bundleArgument arg="mainJar" value="testFxAppWithUtil.jar"/>
            <fx:bundleArgument arg="classpath" value="testFxAppWithUtil.jar;Util.jar"/>
        </fx:deploy>
    </target>
</project>

Output:
$ ant
Buildfile: C:\Users\gtee\AppData\Local\Temp\2\build.xml

fx-deploy:
No base JDK. Package will use system JRE.
  Using default package resource [application icon] (add package/windows/App1.ic o to the class path to customize)
Icon File Name: C:\Cygwin\tmp\fxbundler637518140483349871\windows\App1.ico
Executable File Name: C:\Cygwin\tmp\fxbundler637518140483349871\images\win-exe.i mage\App1\App1.exe
  Config files are saved to C:\Cygwin\tmp\fxbundler637518140483349871\windows. U se them to customize package.
  Config files are saved to C:\Cygwin\tmp\fxbundler637518140483349871\windows. U se them to customize package.
Bundler EXE Installer failed because of java.lang.NullPointerException

BUILD SUCCESSFUL
Total time: 2 seconds