Greetings! I am attempting to run the HelloWorld example for Drools 4. I have Eclipse 3.3 setup on Windows with the Drools plugin. I have created a project with the Drools examples and added all the Drools .jar files to the project. Everything compiles. When I initially ran HelloWorldExample.java it appeared that it could not find the HelloWorld.drl file. So, I moved that file into the same directory as HelloWorldExample.java and ran again. This time I am getting an error that the JDT compiler is not found even though it appears that there are JDT jar files in the Eclipse plugins. I also attempted to run this example under Linux from the command line. In this case I placed all the Drools .jar files into the JRE ext folder and changed the source code to use the Janino compiler by adding: // Set up for the Janino compiler, not Eclipse System.setProperty("drools.dialect.java.compiler", "JANINO"); PackageBuilderConfiguration cfg = new PackageBuilderConfiguration(); JavaDialectConfiguration javaConf = (JavaDialectConfiguration)cfg.getDialectConfiguration("java"); This version compiles with javac and runs with java -cp . HelloWorldExample but gives me an error within the compiler while compiling the .drl file: Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -1 at java.lang.String.substring(String.java:1938) at org.drools.base.ClassTypeResolver.importClass(ClassTypeResolver.java:242) at org.drools.base.ClassTypeResolver.resolveType(ClassTypeResolver.java:158) at org.drools.rule.builder.dialect.mvel.MVELDialect.addImport(MVELDialect.java:257) at org.drools.compiler.DialectRegistry.addImport(DialectRegistry.java:98) at org.drools.compiler.PackageBuilder.mergePackage(PackageBuilder.java:377) at org.drools.compiler.PackageBuilder.newPackage(PackageBuilder.java:350) at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:267) at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:167) at HelloWorldExample.main(HelloWorldExample.java:39) It is dying on this line: builder.addPackageFromDrl( source ); My version of HelloWorldExample.java the same as the given example except for the addition of the lines above for Janino. My ultimate goal is to run this all under Linux, I am not an Eclipse user. Any help getting this working would be greatly appreciated! Ron _________________________________________________________________ Introducing Live Search cashback . It's search that pays you back! http://search.live.com/cashback/?&pkw=form=MIJAAF/publ=HMTGL/crea=int...