title: Fatal error: Null Pointer Exception after Copying the skeleton installer Izpack
body: <p>I am using izpack-dist-5.1.2 jar for creating a simple installer without any java class, but at the time of compilation it is throwing below error on console,
  My compilation command is 
  "C:\Program Files\IzPack\bin>compile D:\izpack\MY_INSTALLER\install.xml -b D:\izpack\MY_INSTALLER"</p>
  
  <pre><code>INFO: Copying the skeleton installer
  -&gt; Fatal error :
  null
  java.lang.NullPointerException
      at com.izforge.izpack.util.IoHelper.copyStreamToJar(IoHelper.java:465)
      at com.izforge.izpack.merge.jar.JarMerge.mergeImpl(JarMerge.java:217)
      at com.izforge.izpack.merge.jar.JarMerge.merge(JarMerge.java:172)
      at 
  com.izforge.izpack.merge.MergeManagerImpl.merge(MergeManagerImpl.java:73)
          at com.izforge.izpack.compiler.packager.impl.PackagerBase.writeSkeletonInstaller(Pa
  ckagerBase.java:484)
         at com.izforge.izpack.compiler.packager.impl.PackagerBase.writeInstaller(PackagerBase.java:407)
      at com.izforge.izpack.compiler.packager.impl.PackagerBase.createInstaller(PackagerBase.java:354)
      at com.izforge.izpack.compiler.Compiler.createInstaller(Compiler.java:161)
      at com.izforge.izpack.compiler.CompilerConfig.executeCompiler(CompilerConfig.java:364)
  at com.izforge.izpack.compiler.bootstrap.CompilerLauncher.main(CompilerLauncher.java:55)
  (tip : use -? to get the commmand line parameters)
  </code></pre>
  
  <p>my install.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="iso-8859-1" standalone="yes" ?&gt;
  &lt;izpack:installation version="5.0"
                   xmlns:izpack="http://izpack.org/schema/installation"
                   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                   xsi:schemaLocation="http://izpack.org/schema/installation 
  http://izpack.org/schema/5.0/izpack-installation-5.0.xsd"&gt;
  
    &lt;info&gt;
     &lt;appname&gt;Test&lt;/appname&gt;
     &lt;appversion&gt;1&lt;/appversion&gt;
   &lt;/info&gt;
  &lt;guiprefs width="600" height="480" resizable="no"&gt;
  &lt;/guiprefs&gt;
  &lt;locale&gt;
   &lt;langpack iso3="eng"/&gt;
  &lt;/locale&gt;
   &lt;panels&gt;
    &lt;panel classname="ShortcutPanel"/&gt;
   &lt;/panels&gt;
   &lt;packs&gt;
    &lt;pack name="Test" required="yes"&gt;
     &lt;description&gt;Description&lt;/description&gt;
    &lt;/pack&gt;
   &lt;/packs&gt;
   &lt;resources&gt;
    &lt;res src="shortcutSpec.xml" id="shortcutSpec.xml"/&gt;
   &lt;/resources&gt;
   &lt;natives&gt;
    &lt;native type="izpack" name="ShellLink_x64.dll"/&gt;
   &lt;/natives&gt;
  &lt;/izpack:installation&gt;
  </code></pre>
  
  <p>and shotcutSpec.xml:</p>
  
  <pre><code>&lt;shortcuts&gt;
   &lt;programGroup defaultName="SteamNet" location="applications"/&gt;
   &lt;shortcut name = "One Click Wonder"
      target = "$INSTALL_PATH\oneclickwonder.bat"
      commandLine = ""
      workingDirectory= "$INSTALL_PATH"
      description="Minimal Desktop Timer"
      iconFile="$INSTALL_PATH\images\header.png"
      iconIndex="0"
      initialState="noShow"
      programGroup="yes"
      desktop="yes"
      applications="yes"
      startMenu="yes"
      startup="yes"/&gt;
  &lt;/shortcuts&gt;
  </code></pre>
  
  <p>Thanks and seeking for the answer. </p>