帮忙看个错误信息

Caused by: java.lang.NoClassDefFoundError: de/odysseus/el/util/SimpleResolver    at org.jbpm.pvm.internal.script.JuelScriptEngineFactory.getScriptEngine(JuelScriptEngineFactory.java:185)    at javax.script.ScriptEngineManager.getEngineByName(ScriptEngineManager.java:205)    at org.jbpm.pvm.internal.script.ScriptManager.evaluate(ScriptManager.java:111)    at org.jbpm.pvm.internal.script.ScriptManager.evaluateExpression(ScriptManager.java:90)    at org.jbpm.pvm.internal.model.ExecutionImpl.resolveAssignmentExpression(ExecutionImpl.java:772)    at org.jbpm.pvm.internal.model.ExecutionImpl.initializeAssignments(ExecutionImpl.java:726)    at org.jbpm.jpdl.internal.activity.TaskActivity.execute(TaskActivity.java:95)    at org.jbpm.jpdl.internal.activity.TaskActivity.execute(TaskActivity.java:58)    at org.jbpm.pvm.internal.model.op.ExecuteActivity.perform(ExecuteActivity.java:60)    at org.jbpm.pvm.internal.model.ExecutionImpl.performAtomicOperationSync(ExecutionImpl.java:656)    at org.jbpm.pvm.internal.model.ExecutionImpl.performAtomicOperation(ExecutionImpl.java:616)    at org.jbpm.pvm.internal.model.ExecutionImpl.start(ExecutionImpl.java:217)    at org.jbpm.pvm.internal.cmd.StartProcessInstanceInLatestCmd.execute(StartProcessInstanceInLatestCmd.java:65)    at org.jbpm.pvm.internal.cmd.StartProcessInstanceInLatestCmd.execute(StartProcessInstanceInLatestCmd.java:38)    at org.jbpm.pvm.internal.svc.DefaultCommandService.execute(DefaultCommandService.java:42)    at org.jbpm.pvm.internal.tx.SpringCommandCallback.doInTransaction(SpringCommandCallback.java:45)    at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:128)    at org.jbpm.pvm.internal.tx.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:55)    at org.jbpm.pvm.internal.svc.EnvironmentInterceptor.executeInNewEnvironment(EnvironmentInterceptor.java:53)    at org.jbpm.pvm.internal.svc.EnvironmentInterceptor.execute(EnvironmentInterceptor.java:40)    at org.jbpm.pvm.internal.svc.RetryInterceptor.execute(RetryInterceptor.java:55)    at org.jbpm.pvm.internal.svc.ExecutionServiceImpl.startProcessInstanceByKey(ExecutionServiceImpl.java:78)    at cn.ait.xkw.licence.service.ProcessServiceImpl.startProcessInstance(ProcessServiceImpl.java:170)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)    at $Proxy29.startProcessInstance(Unknown Source)    at cn.ait.xkw.licence.service.LicenceProjectServiceImpl.startProcess(LicenceProjectServiceImpl.java:429)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)    at $Proxy32.startProcess(Unknown Source)    at cn.ait.xkw.licence.action.LicenceProjectAction.startLicencePrj(LicenceProjectAction.java:522)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)    ... 42 moreCaused by: java.lang.ClassNotFoundException: de.odysseus.el.util.SimpleResolver    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)    at java.security.AccessController.doPrivileged(Native Method)    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)    ... 96 more