I found this error while running the sample of Drools file what is the problem actually. many thanks org.drools.RuntimeDroolsException: Unable to load dialect 'org.drools.rule.builder.dialect.java.JavaDialectConfiguration:java' at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:160) at org.drools.compiler.PackageBuilderConfiguration.buildDialectConfigurationMap(PackageBuilderConfiguration.java:146) at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:121) at org.drools.compiler.PackageBuilderConfiguration.(PackageBuilderConfiguration.java:98) at org.drools.compiler.PackageBuilder.(PackageBuilder.java:124) at org.drools.compiler.PackageBuilder.(PackageBuilder.java:86) at com.sample.DroolsTest.readRule(DroolsTest.java:50) at com.sample.DroolsTest.main(DroolsTest.java:21) Caused by: java.lang.RuntimeException: The Eclipse JDT Core jar is not in the classpath at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.setCompiler(JavaDialectConfiguration.java:91) at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.init(JavaDialectConfiguration.java:52) at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:156) ... 7 more View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4199100#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...