Bug when explode a fighter plane

When i go to explode a fighter plane in an alice world ihave this bug.
Error during simulation.




Alice version: 2.2 6/10/2009



Throwable that caused the error:

java.lang.NullPointerException

at edu.cmu.cs.stage3.alice.core.question.SubjectObjec tQuestion.getValue(SubjectObjectQuestion.java:46)

at edu.cmu.cs.stage3.alice.core.question.SubjectQuest ion.getValue(SubjectQuestion.java:35)

at edu.cmu.cs.stage3.alice.core.Property.evaluateIfNe cessary(Property.java:379)

at edu.cmu.cs.stage3.alice.core.Property.getValue(Pro perty.java:406)

at edu.cmu.cs.stage3.alice.core.property.NumberProper ty.getNumberValue(NumberProperty.java:33)

at edu.cmu.cs.stage3.alice.core.property.NumberProper ty.doubleValue(NumberProperty.java:36)

at edu.cmu.cs.stage3.alice.core.property.NumberProper ty.doubleValue(NumberProperty.java:44)

at edu.cmu.cs.stage3.alice.core.response.MoveAnimatio n$RuntimeMoveAnimation.getVector(MoveAnimation.jav a:42)

at edu.cmu.cs.stage3.alice.core.response.MoveAnimatio n$RuntimeMoveAnimation.prologue(MoveAnimation.java :59)

at edu.cmu.cs.stage3.alice.core.response.DoTogether$R untimeDoTogether.prologue(DoTogether.java:53)

at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.childPrologueIfNecessary(DoInOrder. java:52)

at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.update(DoInOrder.java:97)

at edu.cmu.cs.stage3.alice.core.response.CallToUserDe finedResponse$RuntimeCallToUserDefinedResponse.upd ate(CallToUserDefinedResponse.java:86)

at edu.cmu.cs.stage3.alice.core.behavior.TriggerBehav ior.internalSchedule(TriggerBehavior.java:69)

at edu.cmu.cs.stage3.alice.core.Behavior.schedule(Beh avior.java:226)

at edu.cmu.cs.stage3.alice.core.Sandbox.scheduleBehav iors(Sandbox.java:70)

at edu.cmu.cs.stage3.alice.core.World.scheduleBehavio rs(World.java:444)

at edu.cmu.cs.stage3.alice.core.World.schedule(World. java:486)

at edu.cmu.cs.stage3.alice.core.clock.DefaultClock.sc hedule(DefaultClock.java:99)

at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l$7.run(AuthoringTool.java:702)

at edu.cmu.cs.stage3.alice.authoringtool.util.Default Scheduler.simulateOnce(DefaultScheduler.java:115)

at edu.cmu.cs.stage3.alice.authoringtool.util.Default Scheduler.run(DefaultScheduler.java:76)

at edu.cmu.cs.stage3.scheduler.AbstractScheduler.run( AbstractScheduler.java:45)

at java.awt.event.InvocationEvent.dispatch(Unknown Source)

at java.awt.EventQueue.dispatchEvent(Unknown Source)

at java.awt.EventDispatchThread.pumpOneEventForHierar chy(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source)

at java.awt.Dialog$1.run(Unknown Source)

at java.awt.Dialog$2.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at java.awt.Dialog.show(Unknown Source)

at java.awt.Component.show(Unknown Source)

at java.awt.Component.setVisible(Unknown Source)

at edu.cmu.cs.stage3.swing.DialogManager.showModalDia log(DialogManager.java:60)

at edu.cmu.cs.stage3.swing.DialogManager.showDialog(D ialogManager.java:128)

at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.play(AuthoringTool.java:5159)

at edu.cmu.cs.stage3.alice.authoringtool.Actions$15.a ctionPerformed(Actions.java:168)

at javax.swing.AbstractButton.fireActionPerformed(Unk nown Source)

at javax.swing.AbstractButton$Handler.actionPerformed (Unknown Source)

at javax.swing.DefaultButtonModel.fireActionPerformed (Unknown Source)

at javax.swing.DefaultButtonModel.setPressed(Unknown Source)

at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(Unknown Source)

at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)

at java.awt.Component.processMouseEvent(Unknown Source)

at javax.swing.JComponent.processMouseEvent(Unknown Source)

at java.awt.Component.processEvent(Unknown Source)

at java.awt.Container.processEvent(Unknown Source)

at java.awt.Component.dispatchEventImpl(Unknown Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.LightweightDispatcher.retargetMouseEvent( Unknown Source)

at java.awt.LightweightDispatcher.processMouseEvent(U nknown Source)

at java.awt.LightweightDispatcher.dispatchEvent(Unkno wn Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Window.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.EventQueue.dispatchEvent(Unknown Source)

at java.awt.EventDispatchThread.pumpOneEventForHierar chy(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.run(Unknown Source)