I have been running Jboss 4.2.1 GA for several months, when I switched last week to JBossAS-5.0.0 Beta 4, I started getting this exception after deploying the ear file several times while in the development process. It never happens the first time I deploy it.

17:19:19,328 WARN [HDScanner] Scan failed
org.jboss.deployers.spi.DeploymentException: Exception determining structure: Ab
stractVFSDeployment(Arkit.ear)
at org.jboss.deployers.spi.DeploymentException.rethrowAsDeploymentExcept
ion(DeploymentException.java:49)
at org.jboss.deployers.structure.spi.helpers.AbstractStructuralDeployers
.determineStructure(AbstractStructuralDeployers.java:85)
at org.jboss.deployers.plugins.main.MainDeployerImpl.determineStructure(
MainDeployerImpl.java:743)
at org.jboss.deployers.plugins.main.MainDeployerImpl.addDeployment(MainD
eployerImpl.java:280)
at org.jboss.deployers.plugins.main.MainDeployerImpl.addDeployment(MainD
eployerImpl.java:237)
at org.jboss.system.server.profileservice.hotdeploy.HDScanner.scan(HDSca
nner.java:270)
at org.jboss.system.server.profileservice.hotdeploy.HDScanner.run(HDScan
ner.java:221)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:44
1)
at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java
:317)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.
access$101(ScheduledThreadPoolExecutor.java:98)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.
runPeriodic(ScheduledThreadPoolExecutor.java:181)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.
run(ScheduledThreadPoolExecutor.java:205)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExec
utor.java:885)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:907)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.RuntimeException: Error determining structure: Arkit.ear
at org.jboss.deployment.EARStructure.determineStructure(EARStructure.jav
a:274)
at org.jboss.deployers.vfs.plugins.structure.StructureDeployerWrapper.de
termineStructure(StructureDeployerWrapper.java:65)
at org.jboss.deployers.vfs.plugins.structure.VFSStructuralDeployersImpl.
doDetermineStructure(VFSStructuralDeployersImpl.java:194)
at org.jboss.deployers.vfs.plugins.structure.VFSStructuralDeployersImpl.
determineStructure(VFSStructuralDeployersImpl.java:218)
at org.jboss.deployers.structure.spi.helpers.AbstractStructuralDeployers
.determineStructure(AbstractStructuralDeployers.java:77)
... 14 more
Caused by: java.lang.NullPointerException
at org.jboss.deployment.EARStructure.determineStructure(EARStructure.jav
a:155)
... 18 more