Getting PermissionDeniedException while creation of work item for follow up action

I am working on follow up action using server side api to create work and try to create the work item using implementing the Thread in my logic. I implemented the logic and getting the "PermissionDeniedException while creation of work Item".

Same logic is working fine if I remove the Thread from my code.

Could any one know why I I am getting this exception.

Please find below exception details :

item.com.ibm.team.repository.common.PermissionDeniedException: Missing permission to fetch items

        at com.ibm.team.workitem.service.internal.AuditableServer.resolveAuditablesPermissionAware(AuditableServer.java:161)

        at com.ibm.team.workitem.common.internal.WorkItemCommon.createWorkItem(WorkItemCommon.java:247)

        at com.ibm.team.workitem.common.internal.WorkItemCommon.createWorkItem2(WorkItemCommon.java:232)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)

        at java.lang.reflect.Method.invoke(Method.java:611)

        at com.ibm.team.workitem.service.internal.ServiceAdapter.invoke(ServiceAdapter.java:75)

        at com.sun.proxy.$Proxy2671.createWorkItem2(Unknown Source)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)

        at java.lang.reflect.Method.invoke(Method.java:611)

        at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)

        at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)

        at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)

        at com.sun.proxy.$Proxy2674.createWorkItem2(Unknown Source)

        at com.fcagroup.pmbd.plugin.CRAutoGenerateWI.DynamicDisciplineTaskCreator.createDiscipline(DynamicDisciplineTaskCreator.java:613)

        at com.fcagroup.pmbd.plugin.CRAutoGenerateWI.DynamicDisciplineTaskCreator.createLevelThreeTreeWI(DynamicDisciplineTaskCreator.java:424)

        at com.fcagroup.pmbd.plugin.CRAutoGenerateWI.WorkItemCreation.run(WorkItemCreation.java:47)

com.ibm.team.repository.common.PermissionDeniedException: Missing permission to fetch items