TC ONG [https://community.jboss.org/people/devilkazuya99] created the discussion "ConcurrentModificationException when LocalTaskService.complete()" To view the discussion, visit: https://community.jboss.org/message/745977#745977 -------------------------------------------------------------- I am using jbpm 5.1.2 + drools 5.3.0 When I run the code below, SOMETIMES I get the ConcurrentModificationException. private org.jbpm.task.TaskService localTaskService; ... localTaskService.complete(task1.getId(), actor, contentData); ... Here is the exception I encounter. java.util.ConcurrentModificationException      at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)      at java.util.AbstractList$Itr.next(AbstractList.java:343)      at org.jbpm.task.event.MessagingTaskEventListener.taskCompleted(MessagingTaskEventListener.java:72)      at org.jbpm.task.event.TaskEventSupport.fireTaskCompleted(TaskEventSupport.java:47)      at org.jbpm.task.service.TaskServiceSession.postTaskCompleteOperation(TaskServiceSession.java:497)      at org.jbpm.task.service.TaskServiceSession.taskOperation(TaskServiceSession.java:463)      at org.jbpm.task.service.local.LocalTaskService.complete(LocalTaskService.java:73) Q1: Is it a known bug in this version? Q2: Is it fixed? Q3: Can bypass it? -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/745977#745977] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]