SEVERE [global]
java.util.ConcurrentModificationException
        at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1100)
        at java.util.TreeMap$KeyIterator.next(TreeMap.java:1152)
        at org.openide.nodes.Children$Dupl.updateList(Children.java:2207)
        at org.openide.nodes.Children$Keys.setKeys(Children.java:2000)
        at org.netbeans.spi.java.project.support.ui.PackageViewChildren.refreshKeys(PackageViewChildren.java:202)
        at org.netbeans.spi.java.project.support.ui.PackageViewChildren.access$000(PackageViewChildren.java:92)
        at org.netbeans.spi.java.project.support.ui.PackageViewChildren$1.run(PackageViewChildren.java:211)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
[catch] at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)