tmag [https://community.jboss.org/people/tmag] created the discussion "Timer Job - SingleSessionCommandService - Could not commit session" To view the discussion, visit: https://community.jboss.org/message/761118#761118 -------------------------------------------------------------- We are prototyping  a  process with some timer jobs using JBPM5.3 . And this process is made to be persistent with MySQL. When we are reloading  a session from database with some overdue timer jobs - seeing the following exception in the logs . Did anyone face this issue before? What am missing? Please help. Hibernate: select sessioninf0_.id as id2_0_, sessioninf0_.lastModificationDate as lastModi2_2_0_, sessioninf0_.rulesByteArray as rulesByt3_2_0_, sessioninf0_.startDate as startDate2_0_, sessioninf0_.OPTLOCK as OPTLOCK2_0_ from SessionInfo sessioninf0_ where sessioninf0_.id=? *ERROR SingleSessionCommandService - Could not commit session* *java.lang.NullPointerException*     at org.drools.persistence.SingleSessionCommandService.execute(SingleSessionCommandService.java:367)     at org.drools.persistence.jpa.JpaTimerJobInstance.call(JpaTimerJobInstance.java:34)     at org.drools.persistence.jpa.JpaTimerJobInstance.call(JpaTimerJobInstance.java:14)     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)     at java.util.concurrent.FutureTask.run(FutureTask.java:166)     at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)     at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)     at java.lang.Thread.run(Thread.java:722) WARN  Preparer - executing transaction with 0 enlisted resource *ERROR JpaTimerJobInstance - Unable to execute timer job!* *java.lang.NullPointerException*     at org.drools.persistence.SingleSessionCommandService.execute(SingleSessionCommandService.java:367)     at org.drools.persistence.jpa.JpaTimerJobInstance.call(JpaTimerJobInstance.java:34)     at org.drools.persistence.jpa.JpaTimerJobInstance.call(JpaTimerJobInstance.java:14)     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)     at java.util.concurrent.FutureTask.run(FutureTask.java:166)     at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)     at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)     at java.lang.Thread.run(Thread.java:722) Hibernate: select processins0_.InstanceId as InstanceId0_0_, processins0_.OPTLOCK as OPTLOCK0_0_, processins0_.processId as processId0_0_, processins0_.s https://community.jboss.org/servlet/JiveServlet/showImage/2-761118-19560/... https://community.jboss.org/servlet/JiveServlet/downloadImage/2-761118-19... -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/761118#761118] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]