org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found

Hi ,
The system log showed below error message,
I checked the Bonita engine DB FlowNodeInstance , this flownodeinstance looks fine
Why those error messages showed?

16:25:58,528 ERROR [org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork] (Bonita-Worker-1-01) THREAD_ID=135 | HOSTNAME=tw-aimbpm-dev02 | TENANT_ID=1 | The work [ExecuteFlowNodeWork: processInstanceId:31022, flowNodeInstanceId: 400131] failed. The failure will be handled.
16:25:58,538 ERROR [org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork] (Bonita-Worker-1-01) THREAD_ID=135 | HOSTNAME=tw-aimbpm-dev02 | TENANT_ID=1 | Unexpected error while executing work [ExecuteFlowNodeWork: processInstanceId:31022, flowNodeInstanceId: 400131]. You may consider restarting the system. This will restart all works.: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeExecutionException: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.stepForward(FlowNodeExecutorImpl.java:174) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.executeFlowNode(FlowNodeExecutorImpl.java:317) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.ExecuteFlowNodeWork.work(ExecuteFlowNodeWork.java:72) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork$1.call(TxBonitaWork.java:48) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork$1.call(TxBonitaWork.java:44) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.transaction.JTATransactionServiceImpl.executeInTransaction(JTATransactionServiceImpl.java:312) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork.work(TxBonitaWork.java:53) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.LockProcessInstanceWork.work(LockProcessInstanceWork.java:79) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.work(FailureHandlingBonitaWork.java:66) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaWork.run(BonitaWork.java:56) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.SequenceRunnableExecutor.innerRun(SequenceRunnableExecutor.java:47) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaRunnable.run(BonitaRunnable.java:35) [bonita-server-7.0.1.jar:]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [rt.jar:1.7.0_79]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.7.0_79]
at java.lang.Thread.run(Unknown Source) [rt.jar:1.7.0_79]
Caused by: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.core.process.instance.impl.FlowNodeInstancesServiceImpl.getFlowNodeInstance(FlowNodeInstancesServiceImpl.java:258) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.stepForward(FlowNodeExecutorImpl.java:150) [bonita-server-7.0.1.jar:]
… 17 more

16:25:58,566 ERROR [org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork] (Bonita-Worker-1-01) THREAD_ID=135 | HOSTNAME=tw-aimbpm-dev02 | TENANT_ID=1 | Unable to handle the failure. : org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.core.process.instance.impl.FlowNodeInstancesServiceImpl.getFlowNodeInstance(FlowNodeInstancesServiceImpl.java:258) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.FlowNodeDefinitionAndInstanceContextWork.setExceptionContext(FlowNodeDefinitionAndInstanceContextWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork$1.call(TxInHandleFailureWrappingWork.java:55) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork$1.call(TxInHandleFailureWrappingWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.transaction.JTATransactionServiceImpl.executeInTransaction(JTATransactionServiceImpl.java:312) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.handleFailure(TxInHandleFailureWrappingWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.handleFailureWrappedWork(FailureHandlingBonitaWork.java:106) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.handleFailure(FailureHandlingBonitaWork.java:86) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.work(FailureHandlingBonitaWork.java:71) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaWork.run(BonitaWork.java:56) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.SequenceRunnableExecutor.innerRun(SequenceRunnableExecutor.java:47) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaRunnable.run(BonitaRunnable.java:35) [bonita-server-7.0.1.jar:]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [rt.jar:1.7.0_79]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.7.0_79]
at java.lang.Thread.run(Unknown Source) [rt.jar:1.7.0_79]

16:25:58,595 SEVERE [INCIDENT1] (Bonita-Worker-1-01) An incident occurred: ExecuteFlowNodeWork: processInstanceId:31022, flowNodeInstanceId: 400131
16:25:58,598 SEVERE [INCIDENT1] (Bonita-Worker-1-01) Exception was: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeExecutionException: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.stepForward(FlowNodeExecutorImpl.java:174) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.executeFlowNode(FlowNodeExecutorImpl.java:317) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.ExecuteFlowNodeWork.work(ExecuteFlowNodeWork.java:72) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork$1.call(TxBonitaWork.java:48) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork$1.call(TxBonitaWork.java:44) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.transaction.JTATransactionServiceImpl.executeInTransaction(JTATransactionServiceImpl.java:312) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.TxBonitaWork.work(TxBonitaWork.java:53) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.LockProcessInstanceWork.work(LockProcessInstanceWork.java:79) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.work(TxInHandleFailureWrappingWork.java:42) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.work(FailureHandlingBonitaWork.java:66) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaWork.run(BonitaWork.java:56) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.SequenceRunnableExecutor.innerRun(SequenceRunnableExecutor.java:47) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaRunnable.run(BonitaRunnable.java:35) [bonita-server-7.0.1.jar:]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [rt.jar:1.7.0_79]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.7.0_79]
at java.lang.Thread.run(Unknown Source) [rt.jar:1.7.0_79]
Caused by: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.core.process.instance.impl.FlowNodeInstancesServiceImpl.getFlowNodeInstance(FlowNodeInstancesServiceImpl.java:258) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.FlowNodeExecutorImpl.stepForward(FlowNodeExecutorImpl.java:150) [bonita-server-7.0.1.jar:]
… 17 more

16:25:58,622 SEVERE [INCIDENT1] (Bonita-Worker-1-01) We were unable to handle the failure on the elements because of: org.bonitasoft.engine.core.process.instance.api.exceptions.SFlowNodeNotFoundException: Flow node instance with id 400131 not found
at org.bonitasoft.engine.core.process.instance.impl.FlowNodeInstancesServiceImpl.getFlowNodeInstance(FlowNodeInstancesServiceImpl.java:258) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.FlowNodeDefinitionAndInstanceContextWork.setExceptionContext(FlowNodeDefinitionAndInstanceContextWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork$1.call(TxInHandleFailureWrappingWork.java:55) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork$1.call(TxInHandleFailureWrappingWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.transaction.JTATransactionServiceImpl.executeInTransaction(JTATransactionServiceImpl.java:312) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.failurewrapping.TxInHandleFailureWrappingWork.handleFailure(TxInHandleFailureWrappingWork.java:51) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.handleFailureWrappedWork(FailureHandlingBonitaWork.java:106) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.handleFailure(FailureHandlingBonitaWork.java:86) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.execution.work.FailureHandlingBonitaWork.work(FailureHandlingBonitaWork.java:71) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaWork.run(BonitaWork.java:56) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.SequenceRunnableExecutor.innerRun(SequenceRunnableExecutor.java:47) [bonita-server-7.0.1.jar:]
at org.bonitasoft.engine.work.BonitaRunnable.run(BonitaRunnable.java:35) [bonita-server-7.0.1.jar:]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [rt.jar:1.7.0_79]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.7.0_79]
at java.lang.Thread.run(Unknown Source) [rt.jar:1.7.0_79]