Yeah, I have been having the same issues and seems like there isn't a workaround, I have have spent alot of time and tried everything, starting to believe it's a BUG! I am not creating hardly any code in the attatched program, using objects with already created methods.
Error during simulation.
Alice version: 2.2 8/1/2009
Throwable that caused the error:
java.lang.NullPointerException
at edu.cmu.cs.stage3.alice.core.Behavior$RuntimeStack .pop(Behavior.java:49)
at edu.cmu.cs.stage3.alice.core.Behavior.popStack(Beh avior.java:360)
at edu.cmu.cs.stage3.alice.core.response.CallToUserDe finedResponse$RuntimeCallToUserDefinedResponse.epi logue(CallToUserDefinedResponse.java:95)
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.childrenEpiloguesIf Necessary(CompositeResponse.java:67)
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.epilogue(CompositeR esponse.java:73)
at edu.cmu.cs.stage3.alice.core.response.DoTogether$R untimeDoTogether.epilogue(DoTogether.java:81)
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.childrenEpiloguesIf Necessary(CompositeResponse.java:67)
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.epilogue(CompositeR esponse.java:73)
at edu.cmu.cs.stage3.alice.core.response.LoopNInOrder $RuntimeLoopNInOrder.epilogue(LoopNInOrder.java:99 )
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.childrenEpiloguesIf Necessary(CompositeResponse.java:67)
at edu.cmu.cs.stage3.alice.core.response.CompositeRes ponse$RuntimeCompositeResponse.epilogue(CompositeR esponse.java:73)
at edu.cmu.cs.stage3.alice.core.response.CallToUserDe finedResponse$RuntimeCallToUserDefinedResponse.epi logue(CallToUserDefinedResponse.java:94)
at edu.cmu.cs.stage3.alice.core.behavior.AbstractCond itionalBehavior.internalSchedule(AbstractCondition alBehavior.java:112)
at edu.cmu.cs.stage3.alice.core.behavior.ConditionalB ehavior.internalSchedule(ConditionalBehavior.java: 39)
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:704)
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:58)
at edu.cmu.cs.stage3.swing.DialogManager.showDialog(D ialogManager.java:126)
at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.play(AuthoringTool.java:5091)
at edu.cmu.cs.stage3.alice.authoringtool.Actions$16.a ctionPerformed(Actions.java:175)
at javax.swing.AbstractButton.fireActionPerformed(Unk nown Source)
at javax.swing.AbstractButton$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)