java.lang.IllegalArgumentException: Last path component must be non-null
   at javax.swing.tree.TreePath.<init>(TreePath.java:105)
   at javax.swing.event.TreeModelEvent.<init>(TreeModelEvent.java:131)
   at ru.bitel.common.client.treetable.DefaultBGTreeTableModel.fireTreeStructureChanged(DefaultBGTreeTableModel.java:149)
   at ru.bitel.common.client.treetable.DefaultBGTreeTableModel.setData(DefaultBGTreeTableModel.java:286)
   at ru.bitel.bgbilling.modules.inet.api.client.InetOptionPanel$2.actionPerformedImpl(InetOptionPanel.java:71)
   at ru.bitel.common.client.AbstractBGUPanel.actionPerformed(AbstractBGUPanel.java:237)
   at ru.bitel.common.client.AbstractBGUPanel$DefaultAction.actionPerformed(AbstractBGUPanel.java:91)
   at ru.bitel.bgbilling.client.common.BGServiceConfig.setData(BGServiceConfig.java:487)
   at ru.bitel.bgbilling.client.common.BGServiceConfig.jTabbedPane_stateChanged(BGServiceConfig.java:580)
   at ru.bitel.bgbilling.client.common.BGServiceConfig.access$500(BGServiceConfig.java:42)
   at ru.bitel.bgbilling.client.common.BGServiceConfig$2.stateChanged(BGServiceConfig.java:302)
   at javax.swing.JTabbedPane.fireStateChanged(JTabbedPane.java:416)
   at javax.swing.JTabbedPane$ModelListener.stateChanged(JTabbedPane.java:270)
   at javax.swing.DefaultSingleSelectionModel.fireStateChanged(DefaultSingleSelectionModel.java:132)
   at javax.swing.DefaultSingleSelectionModel.setSelectedIndex(DefaultSingleSelectionModel.java:67)
   at javax.swing.JTabbedPane.setSelectedIndexImpl(JTabbedPane.java:616)
   at javax.swing.JTabbedPane.setSelectedIndex(JTabbedPane.java:591)
   at javax.swing.plaf.basic.BasicTabbedPaneUI$Handler.mousePressed(BasicTabbedPaneUI.java:3647)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
   at java.awt.Component.processMouseEvent(Component.java:6532)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
   at java.awt.Component.processEvent(Component.java:6300)
   at java.awt.Container.processEvent(Container.java:2236)
   at java.awt.Component.dispatchEventImpl(Component.java:4891)
   at java.awt.Container.dispatchEventImpl(Container.java:2294)
   at java.awt.Component.dispatchEvent(Component.java:4713)
   at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
   at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4522)
   at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
   at java.awt.Container.dispatchEventImpl(Container.java:2280)
   at java.awt.Window.dispatchEventImpl(Window.java:2750)
   at java.awt.Component.dispatchEvent(Component.java:4713)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)