[rules-users] [Newbie] XML Package Reader: how to avoid this exception?

[Fabio Genovese]

Hi everybody.

I'm a happy user of the Drools 3.0.5 XML package reader, it seems
working fine, but when I try to include an extra library (not
Drools-related) in my build path, comes up this exception:

Exception in thread "main" java.lang.RuntimeException: AElfred parser is
non-validating
    at org.drools.xml.XmlPackageReader.read(Unknown Source)
    at org.drools.xml.XmlPackageReader.read(Unknown Source)
    at org.drools.compiler.PackageBuilder.addPackageFromXml(Unknown Source)
    at com.sample.PackageWriter.main(PackageWriter.java:39)

It won't occur if I remove this "extra" library from build path (which
uses a XML parser as well).
Maybe I need to specify which parser Drools needs to load, but I don't
know how.
Sorry, I don't have enought java/xml experience to solve this. Could
someone help me?

Thanks in advance.
FG