I added the properties, inserted the users and groups. doesn't help. I turn on the 'hibernate.show_sql', see below.
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INFO 15:21:59,819 (UserGroupCallbackManager.java:34) - UserGroupCallback registered from system property: org.jbpm.task.service.DefaultUserGroupCallbackImpl
Hibernate: select user_.id from OrganizationalEntity user_ where user_.id=?
Hibernate: insert into Task (allowedToDelegate, taskInitiator_id, priority, activationTime, actualOwner_id, createdBy_id, createdOn, documentAccessType, documentContentId, documentType, expirationTime, faultAccessType, faultContentId, faultName, faultType, outputAccessType, outputContentId, outputType, parentId, previousStatus, processId, processInstanceId, processSessionId, skipable, status, workItemId) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: insert into I18NText (language, text) values (?, ?)
Hibernate: insert into I18NText (language, text) values (?, ?)
Hibernate: insert into I18NText (language, text) values (?, ?)
Hibernate: insert into Content (content) values (?)
Hibernate: update Task set allowedToDelegate=?, taskInitiator_id=?, priority=?, activationTime=?, actualOwner_id=?, createdBy_id=?, createdOn=?, documentAccessType=?, documentContentId=?, documentType=?, expirationTime=?, faultAccessType=?, faultContentId=?, faultName=?, faultType=?, outputAccessType=?, outputContentId=?, outputType=?, parentId=?, previousStatus=?, processId=?, processInstanceId=?, processSessionId=?, skipable=?, status=?, workItemId=? where id=?
Hibernate: update I18NText set Task_Descriptions_Id=? where id=?
WARN 15:15:44,558 (JDBCExceptionReporter.java:233) - SQL Error: 1452, SQLState: 23000
ERROR 15:15:44,558 (JDBCExceptionReporter.java:234) - Cannot add or update a child row: a foreign key constraint fails (`mina_task_server_test_db`.`i18ntext`, CONSTRAINT `FK2349686B69B21EE8` FOREIGN KEY (`Task_Descriptions_Id`) REFERENCES `Task` (`id`))