Erro em applet

Pessoa no momento que estou tentando chamar meu applet acontece esse erro. Alguém sabe o que é

Exception in thread "AWT-EventQueue-2" java.lang.IllegalStateException: Applet's parent container not set up at sun.plugin2.applet.Plugin2Manager.start(Unknown Source) at sun.plugin2.main.client.PluginMain$StartAppletRunner.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$500(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) basic: PluginMain.unregisterApplet: 4 from mananger sun.plugin2.applet.Applet2Manager@192e0f4

Alguém ?