Install fails for izpack-dist-5.1.2.jar and other izpack installers on Java 9


Locks up on the installation progress dialog (step 7 of 9 for izpack-dist-5.1.2.jar) with zero complete of both pack installation progress and overall installation progress. See attached screenshot.

Also fails on other installer projects but I figured that failing on izpack-dist-5.1.2.jar would be easy for you to replicate.

I learned of the problem from one of the users of a project that I distribute through my work at the National Institute of Standards and Technology. A user reported the problem.


Windows 7


René Krell
March 19, 2018, 9:44 PM

Thanks, , for checking this.

Mark Soderquist
March 19, 2018, 5:02 PM

It appears that the fix noted below has fixed the ClassCastException noted above. I built IzPack with Java 8, built an installer for my application with it and then ran the installer on Java 9 successfully.

René Krell
March 17, 2018, 10:09 AM

Isn't this a duplicate of or affected by IZPACK-1623?
Actually, the stacktrace is different, but the URLClassLoader has been replaced there.

If yes, a fix has been merged but not released, please pull the current IzPack snapshot from the master branch and give it a try.

We would be glad to have this branch clean regarding installing in JDK9 environments before releasing.

Mark Soderquist
March 17, 2018, 4:06 AM

Here is a stack trace regarding this issue:

Command line arguments:
Cannot find named resource: 'packsLang.xml' AND 'packsLang.xml_eng'
Installation started
Exception in thread "IzPack - Unpacker thread" java.lang.ClassCastException: java.base/jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to java.base/
at com.izforge.izpack.installer.unpacker.UnpackerBase.logIntro(
at com.izforge.izpack.installer.unpacker.UnpackerBase.unpack(
at java.base/

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Nicholaas Ritchie


Functional - may break existing environments