Worlds will not open

This is my homework, I have redone it about 6 times. I have removed Alice from my computer, reinstalled it, and nothing works. I am so frustrated, you have no idea. I have posted the assignment I did, and the error hoping someone can help me. I have asked my instructor, the school tech support and Alice support elsewhere, and keep hitting walls. Anything anyone call tell me will be greatly appreciated. I have Alice 2.2b on my PC.

This is the error I get-

Unable to load world


Alice version: 2.2 8/1/2009

Throwable that caused the error:
java.lang.NullPointerException
at edu.cmu.cs.stage3.alice.core.visualization.Collect ionOfModelsVisualization.getItemsCollection(Collec tionOfModelsVisualization.java:29)
at edu.cmu.cs.stage3.alice.core.visualization.Collect ionOfModelsVisualization.loadCompleted(CollectionO fModelsVisualization.java:153)
at edu.cmu.cs.stage3.alice.core.Element.loadCompleted (Element.java:1426)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1551)
at edu.cmu.cs.stage3.alice.authoringtool.dialog.LoadE lementProgressPane.construct(LoadElementProgressPa ne.java:36)
at edu.cmu.cs.stage3.progress.ProgressPane$2.run(Prog ressPane.java:82)
at java.lang.Thread.run(Unknown Source)

mdgirl. . .

Comment/disable all of your code and repost. I downloaded your program and just like you it would not open. I need to see the animation's code in order to debug it. There is something in the code which is preventing it from loading. If we can not see the source code it will be hard to help you.

Originally Posted by lanceA

mdgirl. . .

Comment/disable all of your code and repost. I downloaded your program and just like you it would not open. I need to see the animation's code in order to debug it. There is something in the code which is preventing it from loading. If we can not see the source code it will be hard to help you.

I do not understand what you mean by "Comment/disable all of your code and repost." If the world won't open, how can I show you a copy of the source code? I am still learning this program, so there are many things I still don't know how to do yet. Thanks.

Originally Posted by mdgirl

I do not understand what you mean by "Comment/disable all of your code and repost." If the world won't open, how can I show you a copy of the source code? I am still learning this program, so there are many things I still don't know how to do yet. Thanks.

You are correct. If you can not open the world then you can not do what I asked. Sorry.

Do you have any Backup folders of your world? Alice automatically backs up your animations.

Originally Posted by lanceA

You are correct. If you can not open the world then you can not do what I asked. Sorry.

Do you have any Backup folders of your world? Alice automatically backs up your animations.

Yes, I have the backups. They will open only if I agree to let me open with a value of zero, which means starting all over again.