Liferay 6.0.6 - Export User Generate Exception Error

• Type: Bug
• Status: Closed
• Resolution: No Longer Reproducible
• Affects Version/s: 6.0.6 GA
• Fix Version/s: 6.1.0 CE RC1, --Sprint 11/12, 6.2.0 CE M2
• Component/s: Legacy, Legacy > Control Panel menu
• Labels:
  • 6.0.6
  • problem
• Environment: Linux - CentOS 5.5; OpenJDK 1.6

Login as super user
go to Control Panel > Users
click on export user button

and it generate exception error
which i attached.