[jamiemitchell]

I have a student who after several hours working on his program, tried to reopen it only to receive the error below. Is there any way to recover from this, and get his project at least editable? (another computer definitely didn't solve the problem) Any ideas what causes these problems, so I can tell students what to avoid in the future?

Unable to load world


Alice version: 2.3.5
os.name: Mac OS X
os.version: 10.8.5
os.arch: x86_64
java.vm.name: Java HotSpot(TM) 64-Bit Server VM
java.vm.version: 20.65-b04-462
user.dir: /Applications/Alice.app/Contents/Required

Throwable that caused the error:
java.lang.RuntimeException: NoSuchMethodException:class javax.vecmath.Matrix4d
at edu.cmu.cs.stage3.alice.core.Property.getValueOf(P roperty.java:578)
at edu.cmu.cs.stage3.alice.core.Property.decodeObject (Property.java:641)
at edu.cmu.cs.stage3.alice.core.Property.decode(Prope rty.java:656)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1478)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1495)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1495)
at edu.cmu.cs.stage3.alice.core.Element.load(Element. java:1543)
at edu.cmu.cs.stage3.alice.authoringtool.dialog.LoadE lementProgressPane.construct(LoadElementProgressPa ne.java:42)
at edu.cmu.cs.stage3.progress.ProgressPane$2.run(Prog ressPane.java:86)
at java.lang.Thread.run(Thread.java:695)