when i finish a task, bug bellows show:
ENGINE-03004 Exception while executing Database Operation 'DELETE ExecutionEntity[4267bbd4-8f88-11ea-b9e3-74e5f9ec77ba]' with message '
### Error flushing statements. Cause: org.apache.ibatis.executor.BatchExecutorException: org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.deleteExecution (batch index #8) failed. 7 prior sub executor(s) completed successfully, but will be rolled back. Cause: java.sql.BatchUpdateException: Cannot delete or update a parent row: a foreign key constraint fails (`dex-wfc`.`act_ru_execution`, CONSTRAINT `ACT_FK_EXE_PARENT` FOREIGN KEY (`PARENT_ID_`) REFERENCES `act_ru_execution` (`ID_`))
### Cause: org.apache.ibatis.executor.BatchExecutorException: org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.deleteExecution (batch index #8) failed. 7 prior sub executor(s) completed successfully, but will be rolled back. Cause: java.sql.BatchUpdateException: Cannot delete or update a parent row: a foreign key constraint fails (`dex-wfc`.`act_ru_execution`, CONSTRAINT `ACT_FK_EXE_PARENT` FOREIGN KEY (`PARENT_ID_`) REFERENCES `act_ru_execution` (`ID_`))'. Flush summary:
[
INSERT HistoricVariableUpdateEventEntity[c9336586-900b-11ea-872d-74e5f9ec77ba]
INSERT HistoricVariableUpdateEventEntity[c9338c97-900b-11ea-872d-74e5f9ec77ba]
INSERT HistoricTaskInstanceEventEntity[c9353a49-900b-11ea-872d-74e5f9ec77ba]
INSERT HistoricActivityInstanceEventEntity[Activity_1ykpr96:c9351338-900b-11ea-872d-74e5f9ec77ba]
INSERT TaskEntity[c9353a49-900b-11ea-872d-74e5f9ec77ba]
DELETE VariableInstanceEntity[42578f1c-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[42578f1e-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[42578f20-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[426041bb-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[426041bc-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[4267bbd5-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[4267e2e6-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE VariableInstanceEntity[4c13a00c-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE TaskEntity[42610513-8f88-11ea-b9e3-74e5f9ec77ba]
UPDATE ExecutionEntity[3863a53d-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE ExecutionEntity[426041ba-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE ExecutionEntity[4267bbd4-8f88-11ea-b9e3-74e5f9ec77ba]
DELETE ExecutionEntity[425719ea-8f88-11ea-b9e3-74e5f9ec77ba]
UPDATE HistoricActivityInstanceEventEntity[425719eb-8f88-11ea-b9e3-74e5f9ec77ba]
UPDATE HistoricTaskInstanceEventEntity[42610513-8f88-11ea-b9e3-74e5f9ec77ba]
UPDATE HistoricVariableInstanceEntity[42578f1e-8f88-11ea-b9e3-74e5f9ec77ba]
UPDATE HistoricVariableInstanceEntity[42578f20-8f88-11ea-b9e3-74e5f9ec77ba]
]