Session timeout when migrating many issues

A user reports getting a session timeout when migrating many issues:

2005-05-25 10:34:47,953 ERROR [action.admin.workflow.WorkflowMigrationManager] Error occurred creating change log: java.lang.IllegalStateException: getAttribute: Session already invalidated
java.lang.IllegalStateException: getAttribute: Session already invalidated
at org.apache.catalina.session.StandardSession.getAttribute(StandardSession.java:953)
at org.apache.catalina.session.StandardSessionFacade.getAttribute(StandardSessionFacade.java:171)
at org.apache.catalina.session.StandardSessionFacade.getAttribute(StandardSessionFacade.java:171)
at webwork.action.factory.SessionMap.get(SessionMap.java:92)
at com.atlassian.jira.web.action.admin.workflow.WorkflowMigrationManager.getRemoteUser(WorkflowMigrationManager.java:211)
at com.atlassian.jira.web.action.admin.workflow.WorkflowMigrationManager.createChangeLog(WorkflowMigrationManager.java:195)
at com.atlassian.jira.web.action.admin.workflow.WorkflowMigrationManager.migrate(WorkflowMigrationManager.java:163)
at com.atlassian.jira.web.action.admin.workflow.scheme.SelectProjectWorkflowSchemeStep2.doExecute(SelectProjectWorkflowSchemeStep2.java:64)
at webwork.action.ActionSupport.execute(ActionSupport.java:153)
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:46)
at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:131)
at com.atlassian.jira.web.dispatcher.JiraServletDispatcher.service(JiraServletDispatcher.java:186)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:142)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:58)

Having the session time out in such a way can be quite disastrous for the consistency of the database.