Unable to load world

[charmedlp]

For my school project, we needed to use Alice. I made two different projects, and saved them two. But, Alice is "unable to load world", with those two files nor their backups. Here's what it says:

Project 1:
Unable to load world
Alice version: 2.2 03/01/2012
os.name: Windows 7
os.version: 6.1
os.arch: x86
java.vm.name: Java HotSpot(TM) Client VM
java.vm.version: 20.0-b11
user.dir: C:\Users\Client\Downloads\Required

Throwable that caused the error:
java.lang.IllegalArgumentException: InputStream cannot be null
at javax.xml.parsers.DocumentBuilder.parse(DocumentBu ilder.java:120)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1441)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1485)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1485)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1533)
at edu.cmu.cs.stage3.alice.authoringtool.dialog.LoadE lementProgressPane.construct(LoadElementProgressPa ne.java:37)
at
edu.cmu.cs.stage3.progress.ProgressPane$2.run(Prog ressPane.java:84)
at java.lang.Thread.run(Thread.java:662)

Project 2:
Unable to load world
Alice version: 2.2 03/01/2012
os.name: Windows 7
os.version: 6.1
os.arch: x86
java.vm.name: Java HotSpot(TM) Client VM
java.vm.version: 20.0-b11
user.dir: C:\Users\Client\Downloads\Required

Throwable that caused the error:
java.lang.IllegalArgumentException: InputStream cannot be null
at javax.xml.parsers.DocumentBuilder.parse(DocumentBu ilder.java:120)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1441)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1485)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1533)
at edu.cmu.cs.stage3.alice.authoringtool.dialog.LoadE lementProgressPane.construct(LoadElementProgressPa ne.java:37)
at
edu.cmu.cs.stage3.progress.ProgressPane$2.run(Prog ressPane.java:84)
at java.lang.Thread.run(Thread.java:662)

I can say that I am kinda upset right now, since I don't wanna start again... How can I adjust this?

I joined the different projects in this message if you want to take a look at the problem(Even if you'll probably not be able to open it...) "Intro" is the first one and "Projet" is the second one.

Thanks in advance for your help!