I'm using trunk (revision 10170), and I'm getting an exception when trying to read errors after calling PackageBuilder.addPackageFromDrl(String, Reader). The getErrors() method spits out this exception: java.lang.ArrayStoreException at java.lang.System.arraycopy(Native Method) at java.util.ArrayList.toArray(ArrayList.java:304) at org.drools.compiler.PackageBuilder.getErrors(PackageBuilder.java:380) (The docs for toArray say that exception is thrown if one of the members of the List is the wrong class for the supplied array.) If I instead call printErrors, I get something more useful: java.lang.ClassCastException: org.drools.lang.ExpanderException at org.drools.compiler.PackageBuilder.printErrors(PackageBuilder.java:390) It looks like someone is putting the wrong kind of exception in the error list. This may be related to some bugs in DSL handling. I had to comment out all the blank lines in my DSL file to get it to suppress some other errors, and if I switch to PackageBuilder.addPackageFromDrl(String), the problem goes away. -- Dirk Bergstrom dirk(a)juniper.net _____________________________________________ Juniper Networks Inc., Computer Geek Tel: 408.745.3182 Fax: 408.745.8905