Annotation: Could not work with top component reference Windows/WindowManager/Editing/explorer/untitled_tc_2.wstcref and update its mode, reason: null
Annotation: Cannot read class: org.netbeans.core.NbSheet
Annotation: Source: Windows/Components/untitled_tc_2.settings
Annotation: Content: 
<?xml version="1.0"?>
<!DOCTYPE settings PUBLIC "-//NetBeans//DTD Session settings 1.0//EN" "http://www.netbeans.org/dtds/sessionsettings-1_0.dtd">
<settings version="1.0">
    <instanceof class="org.netbeans.core.NbSheet"/>
    <instanceof class="org.openide.util.Lookup$Provider"/>
    <instanceof class="java.io.Serializable"/>
    <instanceof class="javax.swing.JComponent"/>
    <instanceof class="javax.accessibility.Accessible"/>
    <instanceof class="java.lang.Object"/>
    <instanceof class="java.awt.image.ImageObserver"/>
    <instanceof class="org.openide.util.HelpCtx$Provider"/>
    <instanceof class="java.awt.Component"/>
    <instanceof class="org.openide.windows.TopComponent"/>
    <instanceof class="java.io.Externalizable"/>
    <instanceof class="java.awt.Container"/>
    <instanceof class="java.awt.MenuContainer"/>
    <serialdata class="org.netbeans.core.NbSheet">
        ACED0005737200296F72672E6F70656E6964652E77696E646F77732E546F70436F6D706F6E656E74245265706C6163657284
        874494BDDF6D6403000078707400196F72672E6E65746265616E732E636F72652E4E6253686565747372000F6A6176612E6C
        616E672E53686F7274684D37133460DA5202000153000576616C7565787200106A6176612E6C616E672E4E756D62657286AC
        951D0B94E08B0200007870000177040000000174001950726F70657274696573206F6620546573744C696272617279707075
        7200205B4C6F72672E6F70656E6964652E6E6F6465732E4E6F64652448616E646C653B3B3A40061E8A642202000078700000
        0001737200226F72672E6E65746265616E732E6170692E6E6F646573326C6F6F6B732E4361636865000004DAE83D49D60200
        024C0005636163686574000F4C6A6176612F7574696C2F4D61703B4C000668616E646C6574001F4C6F72672F6F70656E6964
        652F6E6F6465732F4E6F64652448616E646C653B7870737200116A6176612E7574696C2E486173684D61700507DAC1C31660
        D103000246000A6C6F6164466163746F724900097468726573686F6C6478703F4000000000000C7708000000100000000078
        7077010078
    </serialdata>
</settings>

java.io.IOException
	at org.openide.windows.TopComponent$Replacer.readObject(TopComponent.java:972)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:324)
	at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:838)
	at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1746)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1646)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
	at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.readSerial(XMLSettingsSupport.java:505)
	at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.instanceCreate(XMLSettingsSupport.java:533)
	at org.netbeans.modules.settings.convertors.SerialDataConvertor$SettingsInstance.instanceCreate(SerialDataConvertor.java:350)
	at org.netbeans.core.windows.PersistenceManager.lookupTCInstance(PersistenceManager.java:389)
	at org.netbeans.core.windows.layers.TCRefImpl.getTopComponent(TCRefImpl.java:397)
	at org.netbeans.core.windows.layers.TCRefImpl.updateMode(TCRefImpl.java:210)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.addComponents(ModeData.java:855)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.updateComponents(ModeData.java:669)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.updateAll(ModeData.java:417)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.loadDataSection(ModeData.java:1292)
	at org.netbeans.core.windows.ModeImpl.ensureSectionLoaded(ModeImpl.java:2429)
	at org.netbeans.core.windows.ModeImpl.setVisible(ModeImpl.java:1335)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.setModesVisibility(WorkspaceVisibilityManager.java:544)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.processModes(WorkspaceVisibilityManager.java:381)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.doSetVisible(WorkspaceVisibilityManager.java:187)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.performCommand(WorkspaceVisibilityManager.java:110)
	at org.netbeans.core.windows.DeferredPerformer.processCommand(DeferredPerformer.java:197)
	at org.netbeans.core.windows.DeferredPerformer.stateChanged(DeferredPerformer.java:161)
	at org.netbeans.core.windows.StateManager.fireStateChanged(StateManager.java:128)
	at org.netbeans.core.windows.StateManager.setVisibilityState(StateManager.java:153)
	at org.netbeans.core.windows.StateManager.propertyChange(StateManager.java:175)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:330)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:257)
	at java.awt.Component.firePropertyChange(Component.java:6695)
	at org.netbeans.core.windows.MainWindow.doShowWindow(MainWindow.java:189)
	at org.netbeans.core.windows.MainWindow.access$100(MainWindow.java:51)
[catch] at org.netbeans.core.windows.MainWindow$2.run(MainWindow.java:164)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)
==>
java.lang.NullPointerException
	at org.netbeans.api.nodes2looks.Cache.getNode(Cache.java:43)
	at org.openide.nodes.NodeOp.fromHandles(NodeOp.java:362)
	at org.netbeans.core.NbSheet.readExternal(NbSheet.java:316)
	at org.openide.windows.TopComponent$Replacer.readObject(TopComponent.java:922)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:324)
	at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:838)
	at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1746)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1646)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
	at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.readSerial(XMLSettingsSupport.java:505)
	at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.instanceCreate(XMLSettingsSupport.java:533)
	at org.netbeans.modules.settings.convertors.SerialDataConvertor$SettingsInstance.instanceCreate(SerialDataConvertor.java:350)
	at org.netbeans.core.windows.PersistenceManager.lookupTCInstance(PersistenceManager.java:389)
	at org.netbeans.core.windows.layers.TCRefImpl.getTopComponent(TCRefImpl.java:397)
	at org.netbeans.core.windows.layers.TCRefImpl.updateMode(TCRefImpl.java:210)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.addComponents(ModeData.java:855)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.updateComponents(ModeData.java:669)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.updateAll(ModeData.java:417)
	at org.netbeans.core.windows.layers.ModeData$CookiesImpl.loadDataSection(ModeData.java:1292)
	at org.netbeans.core.windows.ModeImpl.ensureSectionLoaded(ModeImpl.java:2429)
	at org.netbeans.core.windows.ModeImpl.setVisible(ModeImpl.java:1335)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.setModesVisibility(WorkspaceVisibilityManager.java:544)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.processModes(WorkspaceVisibilityManager.java:381)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.doSetVisible(WorkspaceVisibilityManager.java:187)
	at org.netbeans.core.windows.WorkspaceVisibilityManager.performCommand(WorkspaceVisibilityManager.java:110)
	at org.netbeans.core.windows.DeferredPerformer.processCommand(DeferredPerformer.java:197)
	at org.netbeans.core.windows.DeferredPerformer.stateChanged(DeferredPerformer.java:161)
	at org.netbeans.core.windows.StateManager.fireStateChanged(StateManager.java:128)
	at org.netbeans.core.windows.StateManager.setVisibilityState(StateManager.java:153)
	at org.netbeans.core.windows.StateManager.propertyChange(StateManager.java:175)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:330)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:257)
	at java.awt.Component.firePropertyChange(Component.java:6695)
	at org.netbeans.core.windows.MainWindow.doShowWindow(MainWindow.java:189)
	at org.netbeans.core.windows.MainWindow.access$100(MainWindow.java:51)
[catch] at org.netbeans.core.windows.MainWindow$2.run(MainWindow.java:164)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)