Creating ANE - Problem with creating the android package

I get the following error when trying to start an App with a ANE creatd by myself based on http://www.adobe.com/devnet/air/articles/ane-android-devices.html:

dx tool failed:

UNEXPECTED TOP-LEVEL EXCEPTION:

java.lang.IllegalArgumentException: already added: Lcom/adobe/fre/FREASErrorException;

    at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)

    at com.android.dx.dex.file.DexFile.add(DexFile.java:143)

    at com.android.dx.command.dexer.Main.processClass(Main.java:301)

    at com.android.dx.command.dexer.Main.processFileBytes(Main.java:278)

    at com.android.dx.command.dexer.Main.access$100(Main.java:56)

    at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:229)

    at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:244)

    at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:130)

    at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:108)

    at com.android.dx.command.dexer.Main.processOne(Main.java:247)

    at com.android.dx.command.dexer.Main.processAllFiles(Main.java:183)

    at com.android.dx.command.dexer.Main.run(Main.java:139)

    at com.android.dx.command.dexer.Main.main(Main.java:120)

    at com.android.dx.command.Main.main(Main.java:89)

1 error; aborting

Can anyone help me with this?