Every time I hit forward, back, left, or right it doesn't do what i told it to (originally when i first made it) and the error message shows up. Any idea on how to fix this? this is with the 2nd attached file.

The first attached file has the message show up right when the game starts. i started to mess around with it to try to fix this problem. i spent over 6 hours working on this and when my teacher graded it, he failed me because of that error message. now i'm trying to fix it before its too late.
if anybody would be kind enough to tell me whats up with it and potentially help me fix it, that would be truly amazing. Thank you.


Error during simulation.


Alice version: 2.2 12/01/2011

Throwable that caused the error:
edu.cmu.cs.stage3.alice.core.IllegalPropertyValueE xception: element must not be null.
at edu.cmu.cs.stage3.alice.core.response.PropertyAnim ation$RuntimePropertyAnimation.prologue(PropertyAn imation.java:122)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.childPrologueIfNecessary(DoInOrder. java:53)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.update(DoInOrder.java:100)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.childUpdate(DoInOrder.java:58)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.update(DoInOrder.java:101)
at edu.cmu.cs.stage3.alice.core.response.CallToUserDe finedResponse$RuntimeCallToUserDefinedResponse.upd ate(CallToUserDefinedResponse.java:89)
at edu.cmu.cs.stage3.alice.core.response.DoTogether$R untimeDoTogether.update(DoTogether.java:71)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.childUpdate(DoInOrder.java:58)
at edu.cmu.cs.stage3.alice.core.response.DoInOrder$Ru ntimeDoInOrder.update(DoInOrder.java:101)
at edu.cmu.cs.stage3.alice.core.response.CallToUserDe finedResponse$RuntimeCallToUserDefinedResponse.upd ate(CallToUserDefinedResponse.java:89)
at edu.cmu.cs.stage3.alice.core.behavior.TriggerBehav ior.internalSchedule(TriggerBehavior.java:70)
at edu.cmu.cs.stage3.alice.core.Behavior.schedule(Beh avior.java:233)
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:457)
at edu.cmu.cs.stage3.alice.core.World.schedule(World. java:499)
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:693)
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(Invocation Event.java:209)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:641)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 611)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:178)
at java.awt.Dialog$1.run(Dialog.java:1046)
at java.awt.Dialog$3.run(Dialog.java:1098)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Dialog.java:1096)
at java.awt.Component.show(Component.java:1584)
at java.awt.Component.setVisible(Component.java:1536)
at java.awt.Window.setVisible(Window.java:842)
at java.awt.Dialog.setVisible(Dialog.java:986)
at edu.cmu.cs.stage3.swing.DialogManager.showModalDia log(DialogManager.java:61)
at edu.cmu.cs.stage3.swing.DialogManager.showDialog(D ialogManager.java:131)
at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.play(AuthoringTool.java:5229)
at edu.cmu.cs.stage3.alice.authoringtool.Actions$16.a ctionPerformed(Actions.java:177)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEven tMulticaster.java:272)
at java.awt.Component.processMouseEvent(Component.jav a:6288)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:605 3)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4651)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 81)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 81)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectio nPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 613)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)