java.lang.IllegalArgumentException: merger/mergee are not of the same class type: org.netbeans.modules.j2ee.dd.impl.client.model_5_0.ApplicationClient/org.netbeans.modules.j2ee.dd.impl.client.model_6_0.ApplicationClient
        at org.netbeans.modules.schema2beans.BaseBean.mergeTree(BaseBean.java:1873)
        at org.netbeans.modules.schema2beans.BaseBean.mergeTreeRoot(BaseBean.java:1475)
        at org.netbeans.modules.schema2beans.BaseBean.mergeUpdate(BaseBean.java:1400)
        at org.netbeans.modules.schema2beans.BaseBean.merge(BaseBean.java:1381)
        at org.netbeans.modules.j2ee.dd.impl.common.EnclosingBean.merge(EnclosingBean.java:164)
        at org.netbeans.modules.j2ee.dd.impl.client.AppClientProxy.merge(AppClientProxy.java:240)
        at org.netbeans.modules.j2ee.dd.api.client.DDProvider$FCA.fileChanged(DDProvider.java:254)
        at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEventImpl(FCLSupport.java:142)
        at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEvent(FCLSupport.java:125)
        at org.openide.filesystems.FCLSupport.dispatchEvent(FCLSupport.java:102)
        at org.openide.filesystems.FileObject$ED.dispatch(FileObject.java:1071)
        at org.openide.filesystems.EventControl.invokeDispatchers(EventControl.java:205)
        at org.openide.filesystems.EventControl.exitAtomicAction(EventControl.java:179)
        at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:124)
        at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:539)
        at org.openide.filesystems.FileUtil.runAtomicAction(FileUtil.java:503)
        at org.openide.text.DataEditorSupport.saveDocument(DataEditorSupport.java:503)
        at org.netbeans.modules.xml.multiview.XmlMultiViewEditorSupport.doSaveDocument(XmlMultiViewEditorSupport.java:283)
        at org.netbeans.modules.xml.multiview.XmlMultiViewEditorSupport.saveDocument(XmlMultiViewEditorSupport.java:261)
        at org.netbeans.modules.xml.multiview.XmlMultiViewDataObject$DataCache.saveData(XmlMultiViewDataObject.java:464)
        at org.netbeans.modules.xml.multiview.XmlMultiViewEditorSupport.saveDocument(XmlMultiViewEditorSupport.java:250)
        at org.netbeans.modules.xml.multiview.XmlMultiViewDataObject$1.save(XmlMultiViewDataObject.java:99)
        at org.openide.actions.SaveAction.performAction(SaveAction.java:112)
        at org.openide.actions.SaveAction.performAction(SaveAction.java:104)
        at org.openide.util.actions.NodeAction.performAction(NodeAction.java:296)
        at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:127)
        at org.netbeans.modules.openide.util.ActionsBridge.implPerformAction(ActionsBridge.java:83)
        at org.netbeans.modules.openide.util.ActionsBridge.doPerformAction(ActionsBridge.java:64)
        at org.openide.util.actions.CallableSystemAction.actionPerformed(CallableSystemAction.java:123)
        at org.openide.util.actions.NodeAction.actionPerformed(NodeAction.java:284)
        at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1636)
        at javax.swing.JComponent.processKeyBinding(JComponent.java:2851)
        at org.openide.windows.TopComponent.processKeyBinding(TopComponent.java:1013)
        at javax.swing.JComponent.processKeyBindings(JComponent.java:2897)
        at javax.swing.JComponent.processKeyEvent(JComponent.java:2814)
        at java.awt.Component.processEvent(Component.java:6040)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
        at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:704)
        at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:969)
        at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:841)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:668)
        at java.awt.Component.dispatchEventImpl(Component.java:4502)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:117)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)