Seems like this is some timing issue.

java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.next(AbstractList.java:343)
at org.teiid.adminapi.impl.ModelMetaData.getValidationErrors(ModelMetaData.java:222)
at org.teiid.adminapi.impl.ModelMetaData.getErrors(ModelMetaData.java:210)
at org.teiid.adminapi.impl.VDBMetaData.getValidityErrors(VDBMetaData.java:249)
at org.teiid.adminapi.impl.VDBMetaData.isValid(VDBMetaData.java:264)
at org.teiid.deployers.VDBDeployer.loadMetadata(VDBDeployer.java:355)
at org.teiid.deployers.VDBDeployer.access$2(VDBDeployer.java:315)
at org.teiid.deployers.VDBDeployer$1.run(VDBDeployer.java:308)
at org.jboss.util.threadpool.RunnableTaskWrapper.run(RunnableTaskWrapper.java:147)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)