java.util.ConcurrentModificationException
        at java.util.Hashtable$Enumerator.next(Hashtable.java:976)
        at org.netbeans.modules.vcscore.util.VariableInputDialog.updateVariableValues(VariableInputDialog.java:602)
        at org.netbeans.modules.vcscore.util.VariableInputDialog.updateVariableValues(VariableInputDialog.java:592)
        at org.netbeans.modules.vcs.advanced.VcsCustomizer.initAdditionalComponents(VcsCustomizer.java:1946)
        at org.netbeans.modules.vcs.advanced.VcsCustomizer.setObject(VcsCustomizer.java:2451)
[catch] at org.netbeans.core.RootFolderNode.getCustomizer(RootFolderNode.java:306)
        at org.openide.nodes.FilterNode.getCustomizer(FilterNode.java:630)
        at org.netbeans.core.windows.services.NodeOperationImpl.customize(NodeOperationImpl.java:78)
        at org.openide.actions.CustomizeAction.performAction(CustomizeAction.java:29)
        at org.openide.util.actions.NodeAction$3.run(NodeAction.java:440)
        at org.openide.util.actions.CallableSystemAction.doPerformAction(CallableSystemAction.java:135)
        at org.openide.util.actions.NodeAction$DelegateAction.actionPerformed(NodeAction.java:438)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1764)
        at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1817)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:419)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:257)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:289)
        at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1113)
        at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(BasicMenuItemUI.java:943)
        at java.awt.Component.processMouseEvent(Component.java:5134)
        at java.awt.Component.processEvent(Component.java:4931)
        at java.awt.Container.processEvent(Container.java:1566)
        at java.awt.Component.dispatchEventImpl(Component.java:3639)
        at java.awt.Container.dispatchEventImpl(Container.java:1623)
        at java.awt.Component.dispatchEvent(Component.java:3480)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3165)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
        at java.awt.Container.dispatchEventImpl(Container.java:1609)
        at java.awt.Window.dispatchEventImpl(Window.java:1590)
        at java.awt.Component.dispatchEvent(Component.java:3480)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:197)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:144)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:136)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:99)