"Error importing data: java.lang.NullPointerException" when importing in JIRA

Importing zipped backup data from prod to test jira instance fails with following exception: Error importing data: java.lang.NullPointerException

Both instances are of version v4.4.5#66.

error log from

2012-04-23 02:47:11,851 JiraImportTaskExecutionThread-1 INFO anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] Importing data is 89% complete...
2012-04-23 02:47:14,679 JiraImportTaskExecutionThread-1 INFO anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] Importing data is 90% complete...
2012-04-23 02:47:20,242 JiraImportTaskExecutionThread-1 INFO anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] Finished storing Generic Values.
2012-04-23 02:47:20,914 JiraImportTaskExecutionThread-1 ERROR anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] Error importing data: java.lang.NullPointerException
java.lang.NullPointerException
at com.atlassian.activeobjects.backup.ActiveObjectsForeignKeyCreator.create(ActiveObjectsForeignKeyCreator.java:55)
at com.atlassian.activeobjects.backup.ForeignKeyAroundImporter.after(ForeignKeyAroundImporter.java:29)
at com.atlassian.dbexporter.importer.AbstractImporter.importNode(AbstractImporter.java:53)
at com.atlassian.dbexporter.DbImporter.importData(DbImporter.java:73)
at com.atlassian.activeobjects.backup.ActiveObjectsBackup.restore(ActiveObjectsBackup.java:158)
at com.atlassian.jira.bc.dataimport.DefaultDataImportService.restoreActiveObjects(DefaultDataImportService.java:351)
at com.atlassian.jira.bc.dataimport.DefaultDataImportService.performImport(DefaultDataImportService.java:492)
at com.atlassian.jira.bc.dataimport.DefaultDataImportService.doImport(DefaultDataImportService.java:214)
at com.atlassian.jira.web.action.setup.DataImportAsyncCommand.call(DataImportAsyncCommand.java:65)
at com.atlassian.jira.web.action.setup.DataImportAsyncCommand.call(DataImportAsyncCommand.java:28)
at com.atlassian.jira.task.ImportTaskManagerImpl$TaskCallableDecorator.call(ImportTaskManagerImpl.java:147)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at com.atlassian.multitenant.impl.DefaultMultiTenantManager.runForTenant(DefaultMultiTenantManager.java:61)
at com.atlassian.multitenant.juc.MultiTenantExecutors$WrappedRunnable.run(MultiTenantExecutors.java:160)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
2012-04-23 02:47:20,914 JiraImportTaskExecutionThread-1 INFO anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] Importing data is 100% complete...
2012-04-23 02:47:20,914 JiraImportTaskExecutionThread-1 INFO anonymous 163x36x1 kglmiu 10.3.16.242 /secure/SetupImport.jspa [jira.bc.dataimport.DefaultDataImportService] JIRA Data Import has finished.