[rules-users] java.lang.NoSuchMethodError on every Action node

Hi everyone. I've been trying to use Drools for the past month, and sometimes I have problems I can't guess anymore how to solve. This time, every action I try to insert in a ruleflow, I receive a java.lang.NoSuchMethodError. I'm even trying a really simple ruleflow with just one simple action - like System.out.println("Test"); - and all I get is a java.lang.NoSuchMethodError. [ The stack trace: java.lang.NoSuchMethodError: br.com.pst.packages.ruleflows.Process_br_com_pst_packages_ruleflows_0.action0(Lorg/drools/spi/KnowledgeHelper;Lorg/drools/spi/ProcessContext;)V at br.com.pst.packages.ruleflows.Process_br_com_pst_packages_ruleflows_0Action0Invoker.execute( Process_br_com_pst_packages_ruleflows_0Action0Invoker.java:20) at org.drools.workflow.instance.node.ActionNodeInstance.internalTrigger( ActionNodeInstance.java:54) at org.drools.workflow.instance.impl.NodeInstanceImpl.trigger( NodeInstanceImpl.java:111) at org.drools.workflow.instance.impl.NodeInstanceImpl.triggerConnection( NodeInstanceImpl.java:142) at org.drools.workflow.instance.impl.NodeInstanceImpl.triggerCompleted( NodeInstanceImpl.java:128) at org.drools.workflow.instance.node.StartNodeInstance.triggerCompleted( StartNodeInstance.java:49) at org.drools.workflow.instance.node.StartNodeInstance.internalTrigger( StartNodeInstance.java:41) at org.drools.workflow.instance.impl.NodeInstanceImpl.trigger( NodeInstanceImpl.java:111) at org.drools.ruleflow.instance.RuleFlowProcessInstance.internalStart( RuleFlowProcessInstance.java:16) at org.drools.process.instance.impl.ProcessInstanceImpl.start( ProcessInstanceImpl.java:185) at org.drools.workflow.instance.impl.WorkflowProcessInstanceImpl.start( WorkflowProcessInstanceImpl.java:230) at org.drools.common.AbstractWorkingMemory.startProcess( AbstractWorkingMemory.java:1639) at org.drools.common.AbstractWorkingMemory.startProcess( AbstractWorkingMemory.java:1604) at org.drools.impl.StatefulKnowledgeSessionImpl.startProcess( StatefulKnowledgeSessionImpl.java:267) at br.com.pst.packages.ServicePackages.main( ServicePackages.java:99) ] Actually, the beginning problem was with my project, with a process and subprocess. The subprocess works fine, but the main process throws a java.lang.NoSuchMethodError always on any node I put after a specific RuleFlowGroup node. Everyting used to work before, but when I begin to enlarge it, nothing seems to work anymore. And, as I told, I can't always guess the exact problem as the thrown exceptions are very generic. Hope anyone could help me! Thanks a lot ANA FLÁVIA FONSECA DOS SANTOS Analista de Desenvolvimento de Software PST Eletrônica S/A Phone: +55 19 3787 6379 aflavia(a)pst.com.br www.pst.com.br www.positron.com.br