I'm importing my project to netbeans and I am having this exception: Exception in thread "main" java.lang.NoClassDefFoundError: org/drools/compiler/DroolsParserException at java.lang.Class.getDeclaredFields0(Native Method) at java.lang.Class.privateGetDeclaredFields(Class.java:2308) at java.lang.Class.getDeclaredFields(Class.java:1760) at com.thoughtworks.xstream.mapper.AnnotationMapper.processTypes(AnnotationMapper.java:182) Java Result: 1 it happens when I reach the line where I set the configuration file: SolverFactory solverFactory = new XmlSolverFactory("/com/my/proj/planner/solver/plannerSolverConfig.xml"); I'm using now drools 5.5.0.Final without the dsl file that had some issue (see older post), I tested on eclipse with it and it worked perfectly. The path to the file is correct. These are the dependencies, using maven: drools-compiler-5.5.0.Final drools-core-5.5.0.Final drools-planner-core-5.5.0.Final <properties> <org.drools.version>5.5.0.Final</org.drools.version> </properties> <dependency> <groupId>org.drools</groupId> <artifactId>drools-core</artifactId> <version>${org.drools.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>drools-compiler</artifactId> <version>${org.drools.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.drools.planner</groupId> <artifactId>drools-planner-core</artifactId> <version>${org.drools.version}</version> </dependency>