java.lang.IllegalStateException: attempted model write without invoking startTransaction
   at org.netbeans.modules.xml.xam.AbstractModel.validateWrite(AbstractModel.java:418)
   at org.netbeans.modules.xml.xam.AbstractModel.rollbackTransaction(AbstractModel.java:379)
   at org.netbeans.modules.maven.model.Utilities.performPOMModelOperations(Utilities.java:343)
   at org.netbeans.modules.maven.api.ModelUtils.addDependency(ModelUtils.java:105)
   at org.netbeans.modules.maven.nodes.DependenciesNode$AddDependencyAction.actionPerformed(DependenciesNode.java:368)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
   at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
   at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
   at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
   at javax.swing.AbstractButton.doClick(AbstractButton.java:389)
   at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1223)
   at com.apple.laf.AquaMenuItemUI.doClick(AquaMenuItemUI.java:137)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.menuDragMouseReleased(BasicMenuItemUI.java:1327)
   at javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:568)
   at javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:465)
   at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:411)
   at javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:305)
   at javax.swing.plaf.basic.BasicPopupMenuUI$MouseGrabber.eventDispatched(BasicPopupMenuUI.java:807)
   at java.awt.Toolkit$SelectiveAWTEventListener.eventDispatched(Toolkit.java:2353)
   at java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2245)
   at java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2244)
   at java.awt.Toolkit.notifyAWTEventListeners(Toolkit.java:2203)
   at java.awt.Component.dispatchEventImpl(Component.java:4612)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4618)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4282)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4212)
   at java.awt.Container.dispatchEventImpl(Container.java:2129)
   at java.awt.Window.dispatchEventImpl(Window.java:2475)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:130)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)