工作流每个节点都挂起，撤销挂起就通过，是怎么回事？

上一节点审批通过之后，到达下一节点的参与人也有，一开始也是一闪一闪，过了3秒之后就自动挂起了，然后撤销挂起又正常了。

每个节点都如此。这个流程是导出一个原始流程的基础上改的，原始流程都没问题。

太奇怪了，有人遇到过吗？怎么解决？

异常原因是：工作流执行自动活动时出错.源活动【{0}】
------
Caused by: com.kingdee.bos.workflow.WfException :
工作流执行自动活动时出错.源活动【{0}】
Caused by: com.kingdee.bos.workflow.WfException :
null
Caused exception message is: null
java.lang.NullPointerException
at com.kingdee.cbos.process.vm.internal.r.FlowContextImpl.push(FlowContextImpl.java:236)
at com.kingdee.bos.workflow.engine.core.thread.WfTransitExecutor.execute(WfTransitExecutor.java:63)
at com.kingdee.bos.workflow.engine.core.thread.WfJobHandler.handler(WfJobHandler.java:182)
at sun.reflect.GeneratedMethodAccessor409.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.kingdee.bos.workflow.util.InvocationExecutor.execute(InvocationExecutor.java:28)
at com.kingdee.bos.workflow.transaction.WfTxInvoker.invoke(WfTxInvoker.java:33)
at sun.reflect.GeneratedMethodAccessor249.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.kingdee.bos.workflow.metas.InvokeMethodDelegateControllerBean.invoke(InvokeMethodDelegateControllerBean.java:77)
at com.kingdee.bos.workflow.metas.InvokeMethodDelegateControllerBean._invokeRequired(InvokeMethodDelegateControllerBean.java:31)
at com.kingdee.bos.workflow.metas.AbstractInvokeMethodDelegateControllerBean.invokeRequired(AbstractInvokeMethodDelegateControllerBean.java:46)
at sun.reflect.GeneratedMethodAccessor386.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.kingdee.bos.transaction.EJBTxFacade.TxInvokerBean.invoke(TxInvokerBean.java:116)
at com.kingdee.bos.transaction.EJBTxFacade.TxInvokerBean.INVOKE_REQUIRED(TxInvokerBean.java:57)
at com.kingdee.bos.transaction.EJBTxFacade.TxInvokerBean_LocalObjectImpl_2.INVOKE_REQUIRED(Unknown Source)
at com.kingdee.bos.transaction.EJBTransactionProxy.invoke(EJBTransactionProxy.java:171)
at com.kingdee.bos.transaction.EJBTransactionProxy.invoke(EJBTransactionProxy.java:324)
at $Proxy236.invokeRequired(Unknown Source)
at com.kingdee.bos.workflow.metas.InvokeMethodDelegate.invokeRequired(InvokeMethodDelegate.java:61)
at sun.reflect.GeneratedMethodAccessor385.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.kingdee.bos.ResponseInvocationHandler.invoke(ResponseInvocationHandler.java:194)
at $Proxy235.invokeRequired(Unknown Source)
at com.kingdee.bos.workflow.transaction.WfTxHelper.invokeRequired(WfTxHelper.java:83)
at com.kingdee.bos.workflow.engine.core.thread.WfJobHandler.invoke(WfJobHandler.java:72)
at com.kingdee.bos.workflow.engine.core.thread.WfJobHandler.invoke(WfJobHandler.java:170)
at com.kingdee.bos.workflow.engine.core.thread.WfJobHandler.execute(WfJobHandler.java:95)
at com.kingdee.bos.service.job.core.ThreadWorker.execute(ThreadWorker.java:161)
at com.kingdee.bos.service.job.core.ThreadWorker.run(ThreadWorker.java:106)
at java.lang.Thread.run(Thread.java:810)
------