java.util.ConcurrentModificationException
	at java.util.TreeMap$PrivateEntryIterator.nextEntry(Unknown Source)
	at java.util.TreeMap$KeyIterator.next(Unknown Source)
	at com.thoughtworks.xstream.core.util.PrioritizedList$PrioritizedItemIterator.next(PrioritizedList.java:91)
	at com.thoughtworks.xstream.core.DefaultConverterLookup.lookupConverterForType(DefaultConverterLookup.java:55)
	at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:56)
	at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
	at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
	at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
	at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1061)
	at hudson.util.XStream2.unmarshal(XStream2.java:109)
	at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1045)
	at com.thoughtworks.xstream.XStream.fromXML(XStream.java:925)
	at hudson.XmlFile.read(XmlFile.java:143)
	at hudson.model.Items.load(Items.java:220)
	...