error loading my module in openmrs

I am developing a new module in openmrs using task scheduling, through the openmrs, but when I load the module the openmrs not start. and shows the following error in the tomcat logs:

ERROR - AbstractReportsTask.run(62) |2016-05-17 08:01:55,660| An error occurred while running scheduled reporting task java.lang.NullPointerException at org.hibernate.cache.impl.bridge.RegionFactoryCacheProviderBridge.nextTimestamp(RegionFactoryCacheProviderBridge.java:93) at org.hibernate.impl.SessionFactoryImpl.openSession(SessionFactoryImpl.java:639) at org.hibernate.impl.SessionFactoryImpl.openSession(SessionFactoryImpl.java:648) at org.springframework.orm.hibernate3.SessionFactoryUtils.doGetSession(SessionFactoryUtils.java:318) at org.springframework.orm.hibernate3.SessionFactoryUtils.getSession(SessionFactoryUtils.java:200) at org.openmrs.api.db.hibernate.HibernateContextDAO.openSession(HibernateContextDAO.java:245) at sun.reflect.GeneratedMethodAccessor221.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:196) at com.sun.proxy.$Proxy68.openSession(Unknown Source) at org.openmrs.api.context.Context.openSession(Context.java:726) at org.openmrs.module.reporting.report.task.AbstractReportsTask.run(AbstractReportsTask.java:52) at java.util.TimerThread.mainLoop(Unknown Source) at java.util.TimerThread.run(Unknown Source) ERROR - AbstractAddressHierarchyTask.run(39) |2016-05-17 08:21:45,875| An error occurred while running scheduled address hierarchy task java.lang.NullPointerException at org.hibernate.cache.impl.bridge.RegionFactoryCacheProviderBridge.nextTimestamp(RegionFactoryCacheProviderBridge.java:93) at org.hibernate.impl.SessionFactoryImpl.openSession(SessionFactoryImpl.java:639) at org.hibernate.impl.SessionFactoryImpl.openSession(SessionFactoryImpl.java:648) at org.springframework.orm.hibernate3.SessionFactoryUtils.doGetSession(SessionFactoryUtils.java:318) at org.springframework.orm.hibernate3.SessionFactoryUtils.getSession(SessionFactoryUtils.java:200) at org.openmrs.api.db.hibernate.HibernateContextDAO.openSession(HibernateContextDAO.java:245) at sun.reflect.GeneratedMethodAccessor221.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:196) at com.sun.proxy.$Proxy68.openSession(Unknown Source) at org.openmrs.api.context.Context.openSession(Context.java:726) at org.openmrs.module.addresshierarchy.scheduler.AbstractAddressHierarchyTask.run(AbstractAddressHierarchyTask.java:32) at java.util.TimerThread.mainLoop(Unknown Source) at java.util.TimerThread.run(Unknown Source) ERROR - AbstractAddressHierarchyTask.run(39) |2016-05-17 08:31:45,875| An error occurred while running scheduled address hierarchy task java.lang.NullPointerException…AND SO ON